Source: UNIVERSITY OF CALIFORNIA, RIVERSIDE submitted to
IMPROVEMENT OF FRUIT SIZE AND YIELD OF MANDARINS IN CALIFORNIA AND GENETIC ANALYSES OF DATE PALMS AND ORNAMENTAL FOLIAGE PLANTS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
0183805
Grant No.
(N/A)
Project No.
CA-R*-BPS-6687-H
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Oct 1, 2004
Project End Date
Aug 31, 2006
Grant Year
(N/A)
Project Director
CHAO, C. T.
Recipient Organization
UNIVERSITY OF CALIFORNIA, RIVERSIDE
(N/A)
RIVERSIDE,CA 92521
Performing Department
BOTANY AND PLANT SCIENCES
Non Technical Summary
The California citrus industry is changing and growers are planting more seedless mandarins and mandarin hybrids due to the increasing importation of mandarins and market demand. One of my research objectives focuses on solving the small fruit size and low yield of mandarins and mandarin hybrids using plant growth regulators. I will develop strategies to increase the production of large sized fruit, commercially valuable fruit, and enhance the return of growers in California. I will investigate the seediness issue of mandarins and mandarin hybrids as consumers and markets demand completely seedless fruit. I will develop strategies to reduce seeds in mandarins and mandarin hybrids, and establish trials of new mandarins, mandarin hybrids and sweet oranges throughout citrus growing areas in California. Continuous evaluation of new citrus cultivars will ensure the competitiveness of industry in the constantly changing global citrus market. My basic research on the genetic relationships of date palms and ornamental foliage plants will help future germplasm collection, maintenance, and preservation.
Animal Health Component
(N/A)
Research Effort Categories
Basic
25%
Applied
75%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2010999104010%
2011099108020%
2021050108020%
2021621108010%
2022120108010%
2040999101030%
Knowledge Area
202 - Plant Genetic Resources; 204 - Plant Product Quality and Utility (Preharvest); 201 - Plant Genome, Genetics, and Genetic Mechanisms;

Subject Of Investigation
1099 - Tropical/subtropical fruit, general/other; 1621 - Cool season perennial grasses; 2120 - Herbaceous perennials and decorative greens; 1050 - Date; 0999 - Citrus, general/other;

Field Of Science
1080 - Genetics; 1010 - Nutrition and metabolism; 1040 - Molecular biology;
Goals / Objectives
(1.Determine use of 2,4-D for fruit size and yield increase of mandarins and mandarin hybrids in California; (2.Determine compatibility among mandarins and pollen transfer within orchards;(3.To Establish new mandarin cultivar production trials;(4.Conduct study of date palm germplasm from around the world;(5.Conduct genetic analyses of ornamental foliage plants. Citrus is one of the major subtropical fruit crops in California. Mandarins and mandarin hybrids are the fastest growing sector of the industry. Consumers and markets prefer easy peeling, nice color, great taste, and seedless mandarins or mandarin hybrids. The increasing importation of mandarins from Spain, Morocco, and other countries encourages our growers to plant more mandarins and remain competitive in the worldwide mandarin market. This trend will continue for years to come in California. Markets also demand seedless mandarins or mandarin hybrids as more fruit come onto the market. The return between seedless fruit versus seedy fruit can be as high as 4-5 times the difference in price. Growers try to plant new mandarin cultivars in isolation, avoid cross-pollination by compatible pollen sources, and produce seedless mandarin fruit. The compatibility/seediness among different mandarins is a great concern and the appropriate safe distance for isolation is also unclear. Some other main problems associated with planting in isolation are low fruit set, low yield, and small fruit size. I have developed an extensive program to enhance fruit set, yield and fruit size of mandarins and mandarin hybrids using plant growth regulators (PGRs) and fertilizers. By identifying the best application timing and concentration of 2,4 dichlorophenoxyacetic acid (2,4-D), I was able to increase the fruit size and yield of mandarins significantly. California citrus growers will benefit directly from this research starting in either 2004 or 2005. An extra 17 to 37 million dollars return could be generated annually based on this research. The issues of compatibility among mandarins and the necessary isolation distance for prevention of cross-pollination is very useful for citrus growers when they establish new orchards. Long term production trials of new mandarins, mandarin hybrids, and sweet oranges will ensure the long term competitiveness and sustainability of the citrus industry in California. The amplified fragment length polymorphism (AFLP) molecular marker is highly polymorphic and repeatable. Using the AFLP markers, I study the germplasm accessions of date palm (Phoenix dactylifera L.) from California, Egypt, Morocco and Oman. My goal is to clarify the genetic relationship of date palm accessions from around the world and eventually determine the origin of date palm. I also use AFLP markers to study accessions of ornamental foliage plants from many genera and establish the genetic relationship within the genera. The studies of date palms and ornamental foliage plants will offer a tool to identify individual accession, establish the genetic relationship among the accessions, and facilitate future germplasm collection, maintenance, and conservation.
Project Methods
I used foliar applied plant growth regulators and fertilizers to enhance fruit set, fruit size and yield of mandarins and mandarin hybrids in California. I conduct pollination study of mandarins and mandarin hybrids to determine the seediness among different cultivars. I used AFLP markers to identify the pollen parentages of mandarin seedlings from fruit collected at orchards in California and determine how far can compatible pollen travel to cause seeds in mandarins. I conduct long term production trials of new mandarins, mandarin hybrids and sweet oranges. I used AFLP markers to study the genetic relationships among date palm germplasm from around the world and ornamental foliage plants.

Progress 10/01/04 to 08/31/06

Outputs
The PI resigned from UC-Riverside effect on August 31, 2006. Much work is terminated prematurely. However some success was accomplished and many interesting questions remain unanswered. The work on using 2,4-D for enhancing fruit size of mandarins and mandarin hybrids in California has reached its goal. A 24C registration for the use in California was granted by the Department of Pesticide Regulation, California Environmental Protection Agency in December 29, 2004. Additional experiments were carried out since 2004 to obtain additional data. Three years of data for the use on Afourer mandarin and Minneola tangelo were collected by March 2006. The last year data on Afourer mandarin in Southern Kern County showed the best treatment was able to increase large sized fruit nearly 36% and with a three years average of 25% increase of large sized fruit comparing with non-treated trees. PI will continue working on this issue to seek permanent (3C) registration of the use of 2,4-D for fruit size increase of mandarins and mandarin hybrids in California.

Impacts
The new pollination work in 2005-2006 showed evidence of stimulated parthenocarpy in Nules Clementine mandarin. One more season of data will be collected by PI to confirm the first year finding. This work potentially could lead to new orchard planting and management practice that could significantly increase the fruit set and yield of mandarins, mandarin hybrids and lemon in California. New citrus cultivar evaluation effort of PI has established many trials through out California in the past few years. Most of the trials will be taken over by other UC personnel to carry out the evaluation of these new cultivars. PI's laboratory has published many publications on the genetics of date palms in the past few years. Work on Medjool dates from Morocco was published in 2006. Manuscripts of additional work on date palms from Oman and methylation polymorphism of date palm offshoots are in preparation. Work on the genetics of ornamental foliage plants was also one of the foci of PI. Work on 10 other foliage plants were completed, PI and collaborators will finished the manuscripts in the next 2-3 years.

Publications

  • Chao, C. T. 2006. Registration of 2,4-D for fruit size and yield increase of mandarins and mandarin hybrids in California. California Citrus Research Board 2005 Annual Report. p. 7.
  • Chao, C. T. and C. J. Lovatt. 2006. Improving the efficacy of GA3 to increase fruit set and yield of Clementine mandarins in California. California Citrus Research Board 2005 Annual Report. p. 8-9.
  • Chao, C. T. 2006. Production and management strategies for new mandarins in California. California Citrus Research Board 2005 Annual Report. p. 9-10.


Progress 01/01/05 to 12/31/05

Outputs
Citrus is one of the major subtropical fruit crops in California. Mandarins and mandarin hybrids are the fastest growing sector of the industry. Consumers and markets prefer easy peeling, nice color, great taste, and seedless mandarins or mandarin hybrids. The increasing importation of mandarins from Spain, Morocco, and other countries also encourages our growers to plant more mandarins and remain competitive in the worldwide mandarin market. This trend will continue for years to come in California. Markets also demand seedless mandarins or mandarin hybrids as more fruit come onto the market. The return between seedless fruit versus seedy fruit can be as high as 4-5 times the difference in price. Growers try to plant new mandarin cultivars in isolation, avoid cross-pollination by compatible pollen sources, and produce seedless mandarin fruit. The compatibility/seediness among different mandarins is a great concern and the appropriate safe distance for isolation is also unclear. Some other main problems associated with planting in isolation are low fruit set, low yield, and small fruit size. In order to solve the problems of mandarin production in California, I developed a very extensive program to enhance fruit set, yield and fruit size of mandarins and mandarin hybrids using plant growth regulators (PGRs) and fertilizers. By identifying the best application timing and concentration of 2,4 dichlorophenoxyacetic acid (2,4-D) in the past four years, I was able to increase the fruit size and yield of mandarins significantly. An extra 17 to 37 million dollars return could be generated annually based on this research. I also investigate the issues of compatibility among mandarins and the necessary isolation distance for prevention of cross-pollination. The information is very useful for citrus growers when they establish new orchards. I also establish long-term production trials of new mandarins, mandarin hybrids, and sweet oranges throughout California. These new cultivar production trials will ensure the long-term competitiveness and sustainability of the citrus industry in California. The amplified fragment length polymorphism (AFLP) molecular marker is highly polymorphic and repeatable. Using the AFLP markers, I study the germplasm accessions of date palm (Phoenix dactylifera L.) from California, Egypt, Morocco and Oman. My goal is to clarify the genetic relationship of date palm accessions from around the world and eventually determine the origin of date palm. I also use AFLP markers to study accessions of ornamental foliage plants from many genera and establish the genetic relationship within the genera. The studies of date palms and ornamental foliage plants will offer a tool to identify individual accession, establish the genetic relationship among the accessions, and facilitate future germplasm collection, maintenance, and conservation.

Impacts
A 24C registration of the use of 2,4 dichlorophenoxyacetic acid (2,4-D) (CitrusFixTM) for fruit size increase of mandarins and mandarin hybrids in California was granted by the Department of Pesticide Regulation, California Environment Protection Agency in January 2005 based on results from this project. Growers in California could begin using this application for 2005 season. 2005 season is expected to be an OFF year. The real benefit of this application may come in the 2006 season, an anticipated ON year. This application should increase the return for growers in an ON year by significantly increase the fruit size of mandarins and mandarin hybrids. From one of my new mandarin trial, we identified four early season Satsuma mandarins (easy peeling, completely seedless and great taste), two of them, Miyagawa and Xie-Shan, are super early season Satsuma. Preliminary data suggests that these two cultivars could potentially be harvested in San Joaquin Valley of California in early September, may be as early as late August. This early marketing window is at least one month earlier than any seedless mandarin currently available in California and USA. These two new cultivars were released to public in 2005. New planting of these two super early season Satsuma mandarins and Miho Wase Satsuma may occur in the next 3-4 years. We will continue evaluate these new cultivars on different rootstock combinations at more locations through out California.

Publications

  • Chao, C. T. 2005. New early season Satsuma mandarin cultivars for California. Topics in Subtropics Newsletter 3(2): 3-5.
  • Reports to commodity groups: Chao, C. T. 2005. Registration of 2,4-D for fruit size and yield increase of mandarins and mandarin hybrids. California Citrus Research Board 2004 Annual Report. p. 7-8.
  • Fang, J., C. T. Chao, R. J. Henny, and J. Chen. 2005. DNA methylation polymorphism in somaclonal derived cultivars of ornamental aroids. 102st American Society for Horticultural Science Annual Meeting, HortScience 40(4): 1105.
  • Elhoumaizi, M. A., P. S. Devanand, J. Fang and C. T. Chao. 2005. Confirmation of Medjool date palm (Phoenix dactylifera L.) as a landrace variety by study Medjool accessions from Morocco using AFLP markers. 102st American Society for Horticultural Science Annual Meeting, HortScience 40(4): 1121.
  • Chao, C. T., L. Ferguson, and C. J. Lovatt. 2005. Registration of 2,4-D for increasing fruit size of mandarins and mandarin hybrids in California. 32st Annual Conference of the Plant Growth Regulation Society of America, Abstract # 43.
  • Fang, J. and C. T. Chao. 2006. Identification of microRNA in citrus. XIII Plant and Animal Genome Annual Meeting.
  • Fang, J. and C. T. Chao. 2006. Methylation sensitive amplification polymorphism in date palms (Phoenix dactylifera L.) and their offshoots. 103st American Society for Horticultural Science Annual Meeting, New Orleans, LA., July 27-30, 2006.
  • Fang, J. and C. T. Chao. 2006. Identification of microRNA in citrus. 103st American Society for Horticultural Science Annual Meeting, New Orleans, LA., July 27-30, 2006.
  • Fang, J., T. Twito, Z. Zhang, and C. T. Chao. 2006. Genetic relationship of fruiting-mei (Prunus mume Sieb. et Zucc.) cultivars revealed by AFLP and SNP markers. 103st American Society for Horticultural Science Annual Meeting, New Orleans, LA., July 27-30, 2006.
  • Chen, J., R. J. Henny, P. S. Devanand, and C. T. Chao. 2006. Genetic relationships of Spathiphyllum cultivars analyzed by AFLP markers. 103st American Society for Horticultural Science Annual Meeting, New Orleans, LA., July 27-30, 2006.
  • Newsletter: Chao, C. T. 2005. New 24C registration of Isopropyl Ester 2,4-D (Alco Citrus Fix) for fruit size increase of mandarins and mandarin hybrids in California. Topics in Subtropics Newsletter 3(1): 4-6.
  • Chao, C. T. and C. J. Lovatt. 2005. Improving efficacy of GA3 to increase fruit set and yield of Clementine mandarins in California. California Citrus Research Board 2004 Annual Report. p. 8.
  • Chao, C. T., C. J. Lovatt, and L. Ferguson. 2005. Application of plant growth regulators and/or fertilizers to increase fruit set, fruit size and yield of Clementine mandarin. California Citrus Research Board 2004 Annual Report. p. 15-18.
  • Stover, E., W. Castle, and C. T. Chao. 2005. Trends in U.S. Sweet orange, grapefruit and mandarin-type scion cultivars. HortTechnology 15(3): 501-506.
  • Chen, J., R. J. Henny, P. S. Devanand, and C. T. Chao. 2006. AFLP marker analysis of nephthytis (Syngonium podophyllum Schott) selected from somaclonal variants. Plant Cell Report 24: 743-749.
  • Fang, J., P.S. Devanand, and C.T. Chao. 2005. Practical strategy of single-nucleotide-polymorphism discovery in fruiting-mei (Prunus mume Sieb. et Zucc.) from AFLP fragments. Plant Molecular Biology Reporter 23: 227-239.
  • Elhoumaizi, M.A., P.S. Devanand, J. Fang, and C.T. Chao. 2006. Confirmation of Medjool date as a landrace variety through genetic analysis of Medjool accessions in Morocco. J. Amer. Soc. Hort. Sci. (In press)
  • Chapters and Symposia Proceedingsa/ Paull, R. R. and C. T. Chao. 2006. Avocado, in The Encyclopedia of Fruits and Nuts, Editor, J. Janick. CAB International, Wallingford, Oxon, UK. (In press)
  • Chao, C. T. and R. R. Krueger. 2006. Date Palm, in The Encyclopedia of Fruits and Nuts, Editor, J. Janick. CAB International, Wallingford, Oxon, UK. (In press)
  • Chao, C. T. and C. J. Lovatt. 2006. Effects of GA3 concentration and application time on fruit set and fruit size of Clementine mandarin in California. Acta Horticulturae (In press)
  • Abstract: Khan, I. A., P. S. Devanand, J. Fang, and C. T. Chao. 2005. Genetic diversity of date palm (Phoenix dactylifera L.) accessions from Oman determined by AFLP markers. First International conference on mango and date palm, culture and export. Faisalabad, Pakistan.
  • Chao, C. T. and C. J. Lovatt. Effects of GA3 concentration and application time on fruit set and fruit size of Clementine mandarin in California. 10th International Symposium on Plant Biogrgulators in Fruit Production. Saltillo, Mexico, June 26-30, 2005, p.75.
  • Chao, C. T. 2005. The date: overview of biology, cultivars and uses. 102st American Society for Horticultural Science Annual Meeting and American Pomological Society Meeting, HortScience 40(4): 952-953.
  • Fang, J., P. S. Devanand, C. T. Chao, P. A. Roberts and J. D. Ehlers. 2005. Genetic diversity of cowpea [Vigna unguiculata (L.) Walp.] breeding lines from different countries determined by AFLP markers. 102st American Society for Horticultural Science Annual Meeting, HortScience 40(4): 998.
  • Chao, C. T. 2005. Preliminary evaluation of 17 Satsuma mandarin (Citrus unshiu Marco.) cultivars in coastal region of California. 102st American Society for Horticultural Science Annual Meeting, HortScience 40(4): 1047.


Progress 01/01/04 to 12/31/04

Outputs
Citrus is one of the major subtropical fruit crops in California. Mandarins and mandarin hybrids are the fastest growing sector of the industry. Consumers and markets prefer easy peeling, nice color, great taste, and seedless mandarins or mandarin hybrids. The increasing importation of mandarins from Spain, Morocco, and other countries also encourages our growers to plant more mandarins and remain competitive in the worldwide mandarin market. This trend will continue for years to come in California. Markets also demand seedless mandarins or mandarin hybrids as more fruit come onto the market. The return between seedless fruit versus seedy fruit can be as high as 4-5 times the difference in price. Growers try to plant new mandarin cultivars in isolation, avoid cross-pollination by compatible pollen sources, and produce seedless mandarin fruit. The compatibility/seediness among different mandarins is a great concern and the appropriate safe distance for isolation is also unclear. Some other main problems associated with planting in isolation are low fruit set, low yield, and small fruit size. In order to solve the problems of mandarin production in California, I developed a very extensive program to enhance fruit set, yield and fruit size of mandarins and mandarin hybrids using plant growth regulators (PGRs) and fertilizers. By identifying the best application timing and concentration of 2,4 dichlorophenoxyacetic acid (2,4-D) in the past three years, I was able to increase the fruit size and yield of mandarins significantly. California citrus growers will benefit directly from this research starting either 2004 or 2005. An extra 17 to 37 million dollars return could be generated annually based on this research. I also investigate the issues of compatibility among mandarins and the necessary isolation distance for prevention of cross-pollination. The information is very useful for citrus growers when they establish new orchards. I also establish long-term production trials of new mandarins, mandarin hybrids, and sweet oranges throughout California. These new cultivar production trials will ensure the long-term competitiveness and sustainability of the citrus industry in California. The amplified fragment length polymorphism (AFLP) molecular marker is highly polymorphic and repeatable. Using the AFLP markers, I study the germplasm accessions of date palm (Phoenix dactylifera L.) from California, Egypt, Morocco and Oman. My goal is to clarify the genetic relationship of date palm accessions from around the world and eventually determine the origin of date palm. I also use AFLP markers to study accessions of ornamental foliage plants from many genera and establish the genetic relationship within the genera. The studies of date palms and ornamental foliage plants will offer a tool to identify individual accession, establish the genetic relationship among the accessions, and facilitate future germplasm collection, maintenance, and conservation.

Impacts
A 24C registration of the use of 2,4 dichlorophenoxyacetic acid (2,4-D) (CitrusFixTM) for fruit size increase of mandarins and mandarin hybrids in California was granted by the Department of Pesticide Regulation, California Environment Protection Agency in January 2005 based on results from this project. Growers in California could begin using this application for 2005 season. 2005 season is expected to be an OFF year. The real benefit of this application may come in the 2006 season, an anticipated ON year. This application should increase the return for growers in an ON year by significantly increase the fruit size of mandarins and mandarin hybrids. From one of my new mandarin trial, we identified four early season Satsuma mandarins (easy peeling, completely seedless and great taste), two of them, Miyagawa and Xie-Shan, are super early season Satsuma. Preliminary data suggests that these two cultivars could potentially be harvested in San Joaquin Valley of California in early September, may be as early as late August. This early marketing window is at least one month earlier than any seedless mandarin currently available in California and USA. Growers in California are eagerly waiting for the release of these two new cultivars. Large planting of these two super early season Satsuma mandarins may occur in the next 3-4 years. We will continue evaluate these new cultivars on different rootstock combinations at more locations through out California.

Publications

  • Fang, J., P. S. Devanand, and C. T. Chao. 2005. Sing-nucleotide-polymorphism isolation in fruiting-mei (Prunus mume Sieb. et Zucc.) from AFLP fragments. XII Plant and Animal Genome Annual Meeting. (P186).
  • Newsletter: Chao, C. T. 2004. Compatibility/seediness among Clementine mandarins, Afourer mandarin, Tahoe Gold mandarin and Gold Nugget mandarin; Implication for seedless mandarin production in California. Topics in Subtropics Newsletter V.2(1): 3-4.
  • Khan, T. and C. T. Chao. 2004. Mysteries of mandarins: sex, seedlessness, and new varieties. California Citrus Mutual Journal 2004: 26-31.
  • Reports to commodity groups: Chao, C. T., C. J. Lovatt, and L. Ferguson. 2004. Application of plant growth regulators and/or fertilizers to increase fruit size and yield of Clementine mandarin. California Citrus Research Board 2003 Annual Report. p. 6-8.
  • Chao, C. T. 2004. Production and management strategies for new mandarins in California. California Citrus Research Board 2003 Annual Report. p. 8-9.
  • El-Assar, A. M., R. R. Krueger, P. S. Devanand, and C. T. Chao. 2005. Genetic analysis of Egyptian date (Phoenix dactylifera L.) accessions using AFLP markers. Genetic Resources and Crop Evolution (In press)
  • Chao, C. T. 2005. Pollination study of mandarins and effect on seediness and fruit size; Implication for seedless mandarin production. HortScience (In press)
  • Fang, J., Y. Qiao, Z. Zhang, and C. T. Chao. 2005. Genotyping fruiting-mei (Prunus mume Sieb. et Zucc) cultivars using AFLP markers. HortScience (In press)
  • Chao, C. T., J. Fang and P. S. Devanand. 2005. Long distance pollen flow in mandarin orchards determined by AFLP markers; Implication for seedless mandarin production. J. Amer. Soc. Hort. Sci. (In press)
  • Chao, C. T., P. S. Devanand, and J. J. Chen. 2005. Assessment of genetic relationships among Calathea species and cultivars by AFLP analysis. Plant Science (In press)
  • Abstract: Chao, C. T. and P. S. Devanand. 2004. Hand cross-pollination study of mandarins and using AFLP markers to identify pollen parentages of mandarins; Implication for seedless mandarin production in California. Proceedings International Society of Citriculture X Congress 2004, Abstract #18.
  • Chao, C. T., C. J. Lovatt, and L. Ferguson. 2004. Application of plant growth regulators and fertilizers to increase fruit set, yield and fruit size of Fina Sodea Clementine mandarin in California. Proceedings International Society of Citriculture X Congress 2004, Abstract#171.
  • Chao, C. T. and P. S. Devanand. 2004. Determination of pollen parentages of mandarin seedlings using AFLP markers and implication for seedless mandarin production in California. 101st American Society for Horticultural Science Annual Meeting, HortScience 39(4): 859.
  • Chao, C. T. 2004. Pollination study of Clementine mandarins, Afourer mandarin, Tahoe Gold mandarin and effect on fruit set and seediness in California. 101st American Society for Horticultural Science Annual Meeting, HortScience 39(4): 859.
  • Chao, C. T., P. S. Devanand, J. J. Chen and R. J. Henny. 2004. AFLP marker analysis of somaclonal variation derived cultivars of Syngonium. American Society of Plant Biologist Annual Meeting, Abstract # 850.
  • Chao, C. T. and P. S. Devanand. 2004. Pollen flow in mandarin orchards and cross-pollination effect on seed content and fruit size of mandarins. 31st Annual Conference of the Plant Growth Regulation Society of America, Abstract #38.
  • Chao, C.T., L. Ferguson, and C. J. Lovatt. 2004. 2,4-D increase the yield of commercially valuable large size fruit of Clementine mandarin. 31st Annual Conference of the Plant Growth Regulation Society of America, Abstract # 63.
  • Chen, J. J., R. J. Henny, C. T. Chao, and P. S. Devanand. 2004. Analysis of genetic relationships of Calathea species and cultivars by AFLP markers. 101st American Society for Horticultural Science Annual Meeting, HortScience 39(4): 888.
  • Devanand, P. S., C. T. Chao, J. J. Chen, and R. J. Henny. 2004. AFLP analysis of genetic relationships among container-grown Anthurium cultivars. 101st American Society for Horticultural Science Annual Meeting, HortScience 39(4): 861.
  • Chen, J. J., P. S. Devanand, D. J. Norman, R. J. Henny, and C. T. Chao. 2004. Genetic relationships of Aglaonema species and cultivars inferred from AFLP markers. Annals of Botany 93(2): 157-166.
  • Chen, J. J., P. S. Devanand, R. J. Henny, D. J. Norman, and C. T. Chao. 2004. Interspecific relationships of Alocasia revealed by AFLP analysis. J. Hort. Sci. & Biotechnology 79(4): 582-586.
  • Devanand, P. S., J. J. Chen, R. J. Henny, and C. T. Chao. 2004. Assessment of genetic relationships among Philodendron cultivars using AFLP markers. J. Amer. Soc. Hort. Sci. 129(5): 690-697
  • Chen, J. J., R. J. Henny, D. J. Norman, P.S. Devanand, and C. T. Chao. 2004. Analysis of genetic relatedness of Dieffenbachia cultivars using AFLP markers. J. Amer. Soc. Hort. Sci. 129(1): 81-87.


Progress 01/01/03 to 12/31/03

Outputs
Our two years old topwork new Satsuma mandarin trial at Santa Paula, CA bore fruit the first time in 2003. Four of the early Satsuma cultivars colored up in the beginning of October 2003 and the fruit quality was excellent. We finished planting of two large trials of new sweet oranges and mandarins at UC Lindcove Research and Extension Center in 2003. We repeated the fertilizer and plant growth regulators experiment on Fina Sodea Clementine mandarin. We initiated a new study of using 2,4-D to increase fruit size of Clementine mandarin, Afourer mandarin, Fairchild mandarin and Minneola tangelo. We completed the first year pollination study of Clementine mandarin, Afourer mandarin, and Tahoe Gold mandarin. We repeated the study again in spring 2003. We completed a study using AFLP markers to determine the pollen parentages of seedlings of Nules Clementine mandarin and Afourer mandarin. We were able to determine how far can the compatible pollens travel to cause seeds in those two mandarins. We finished AFLP marker studies of following materials: (1) Egyptian date palms, (2) Avocado accessions from Mexico, (3) Dieffenbachia spp., (4) Aglaonema spp., (5) Alocasia spp., (6) Philodendron spp., (7) Anthurium spp., (8) Spathiphyllum spp., (9) Syngonium spp.

Impacts
Our topwork Satsuma mandarin trial identified 4 early Satsuma mandarin cultivars that colored up in early October. There is NO mandarin in the early October market. If these four new cultivars can produce excellent fruit in October consistently, the fruit should potentially command great price in the market. This will offer a desperately needed alternative for the Valencia orange growers in Ventura County, CA. Our fertilizer and plant growth regulator study on Fina Sodea identified treatment of 2,4-D that increased yield by 26% and large sized fruit by 41% in 2002 season. This finding translated to additional profit of $2,500 - $4,000 per acre. Our pollination study determined the compatibility between different mandarin cultivars and how seedy they could be. These results have important implication for seedless mandarin production in CA. Our AFLP marker study was able to identify pollen traveled from much larger distance to pollinate Nules Clementine mandarin and Afourer mandarin than expected. These results also have very important implication for seedless mandarin production in CA. Our various AFLP marker studies were able to determine the genetic relationship among different germplasm, cultivars, and species of dates from Egypt, avocados from Mexico and ornamental foliage plants.

Publications

  • Chen, J. J., R. J. Henny, D. J. Norman, P.S. Devanand and C. T. Chao. 2004. Analysis of genetic relatedness of Dieffenbachia cultivars using AFLP markers. J. Amer. Soc. Hort. Sci. 129: 81-87.
  • Devanand, P. S. and C. T. Chao. 2003. Genetic variation within Medjool and Deglet Noor date (Phoenix dactylifera L.) cultivars in California detected by fluorescent-AFLP markers. J. Hort. Sci. & Biotechnology 78(5): 405-409.
  • Chao, C. T., D. E. Parfitt, L. Ferguson, C. Kallsen, and J. Maranto. 2003. Genetic analysis of phenological traits of pistachio (Pistacia vera). Euphytica 129(3): 345-349.
  • Chen, J. J., C. T. Chao, D. J. Norman, R. J. Henny, and P. S. Devanand. 2003. Genetic relatedness of Aglaonema species and cultivars characterized by fluorescent-AFLP markers. 100th American Society for Horticultural Science Annual Meeting, Oct. 3-6, 2003, Providence, R.I., HortScience 38(5): 737. (Abstract)
  • Chao, C. T., L. Ferguson, and C. J. Lovatt. 2003. Effect of 2,4-D and 3,5,6-TPA on yield, fruit size, and fruit quality of Clementine mandarin in California. 100th American Society for Horticultural Science Annual Meeting, Oct. 3-6, 2003, Providence, R.I., HortScience 38(5): 825. (Abstract)
  • Chao, C. T. 2003. Relationship between crop load, fruit size, and number of fruit per branch of Gold Nugget mandarin (Citrus reticulata Blanco). 100th American Society for Horticultural Science Annual Meeting, Oct. 3-6, 2003, Providence, R.I., HortScience 38(5): 838. (Abstract #324)
  • Chao, C. T., J. C., Reyes-Aleman, A. F. Barrientos-Priego, and P. S. Devanand. 2003. Genetic relationships among avocado (Persea americana) accessions from California and Mexico characterized by fluorescent-AFLP markers. V World Avocado Congress, Oct. 19-24, 2003, Granda-Malaga, Spain. (Abstract #A79)
  • Chao, C. T., L. Ferguson and C. J. Lovatt. 2003. Application of 2,4-D and 3,5,6-TPA to increase yield and fruit size of Clementine mandarin in California. 30th Annual conference of the Plant Growth Regulation Society of America and Japanese Society for Chemical Regulation of Plants, Aug. 3-6, 2003, Vancouver, British Columbia, Canada. PGRSA Quarterly 31(2): 87. (Abstract #18)
  • Chao, C. T., J. C. Reyes-Aleman, A. F. Barrientos-Priego and P. S. Devanand. 2003. Genetic diversity of Mexican avocados (Persea americana var. drymifolia) from Mexico determined by fluorescent-AFLP markers. 100th American Society for Horticultural Science Annual Meeting, Oct. 3-6, 2003, Providence, R.I., HortScience 38(5): 663. (Abstract)
  • Chen, J. J., C. T. Chao, D. J. Norman, R. J. Henny, and P. S. Devanand. 2003. Analysis of genetic diversity among Dieffenbachia cultivars using AFLP markers. 100th American Society for Horticultural Science Annual Meeting, Oct. 3-6, 2003, Providence, R.I., HortScience 38(5): 733. (Abstract #220)
  • El-Assar, A.M., R. R. Krueger, and P. S. Devanand, C.T. Chao. 2003. Genetic analyses of date palms (Phoenix dactylifera L.) from Egypt using fluorescent-AFLP markers. 100th American Society for Horticultural Science Annual Meeting, Oct. 3-6, 2003, Providence, R.I., HortScience 38(5): 734. (Abstract #221)
  • Chao, C. T., and P. S. Devanand. 2003. Genetic diversity of avocado rootstocks (Persea americana Mill.) determined by fluorescent-AFLP markers. 100th American Society for Horticultural Science Annual Meeting, Oct. 3-6, 2003, Providence, R.I., HortScience 83(5): 737. (Abstract)
  • Chao, C. T., J. J. Chen, D. J. Norman, R. J. Henny, and P. S. Devanand. 2003. Genetic relationships among cultivated Philodendron analyzed by AFLP markers. 100th American Society for Horticultural Science Annual Meeting, Oct. 3-6, 2003, Providence, R.I., HortScience 38(5): 737. (Abstract)


Progress 01/01/02 to 12/31/02

Outputs
Field trials of Clementine mandarins, new Satsuma mandarins, and new mandarin hybrids cultvars are underway in multiple locations through out California since 2000. The Clementine mandarin trials include 7 cultivars and 5 rootstocks combinations. Planting of Clementine mandarins trials started in Spring of 2002 and will be completed in Spring of 2003. Study of management and production strategies for new mandarin hybrids and Clementine mandarins in California started in 2000. Treatments designed to increase fruit set, fruit size and yield were applied to `Fina Sodea' Clementine mandarin in 2001 and 2002. AFLP markers analyses of date palm cultivars from California was finished in 2001; analyses of genetic variation of date palm cultivars was completed in 2002; analyses of avocado rootstocks from California also accomplished in 2002.

Impacts
In our 2002 experiment of Clementine mandarin management, we identified treatments that could significantly increase yield and size of Clementine mandarin. We will fine-tune the treatments in the next 3-5 years and these treatments should be a very useful tool for growers. Our AFLP markers research of date palm suggested the possibility of landrace variety of date palm. This is the first study ever to suggest this possibility. Our AFLP markers research of avocado rootstocks suggests the further genetic division within the Mexican and West Indian avocados from California.

Publications

  • Cao, B.R. and C.T. Chao. 2002. Identification of date palm cultivars in California using AFLP markers. 37(6): 966-968.
  • Chao, C. T., D. E. Parfitt, L. Ferguson, C. Kallsen, and J. Maranto. 2003. Genetic analysis of phenological traits of pistachio (Pistacia vera). 129(3): 345-349.
  • Devanand, P.S. and C.T. Chao. 2003. Genetic variation within `Medjool' and `Deglet Noor' date (Phoenix dactylifera L.) cultivars in California detected by fluorescent-AFLP markers. J. Hort. Sci. & Biotechnology (In press).
  • Chao, C.T. and J. Doty. 2002. Opening the U.S. citrus market window, Valencias getting you down? Consider some alternatives. Citragraph January-Feburary: 8-11.
  • Chao, C.T., C.J. Lovatt, and L. Ferguson. 2002. Effects of 2,4-D and 3,5,6-TPA on yield, fruit size, and fruit quality of `Fina Sodea' Clementine mandarin in California. 29th Annual conference of the Plant Growth Regulation Society of America, July 28 - August 1, 2002, Halifax, Nova Scotia, Canada. PGRSA Quarterly 30(2): 61 (Abstract).
  • Chao, C.T., C.J. Lovatt, and L. Ferguson. 2002. Effects of GA3, 2,4-D, and AVG on delaying harvest of `Fina Sodea' Clementine mandarin in California. 29th Annual conference of the Plant Growth Regulation Society of America, July 28 - August 1, 2002, Halifax, Nova Scotia, Canada. PGRSA Quarterly 30(2): 74 (Abstract).


Progress 01/01/01 to 12/31/01

Outputs
Field trials of Clementine mandarins, new Satsuma mandarins, and new mandarin hybrid cultivars are underway in multiple locations through out California since 2000. The Clementine mandarin trials include 7 cultivars and 5 rootstocks combination. All 7 locations through out California will be planted in Spring of 2002. The Satsuma mandarins trials include 18 cultivars and 3 rootstocks combination. The planting will be completed in 2003. Study of management and production strategies for new mandarin hybrids and Clementine mandarins in California started in 2000. Treatments designed to increase fruit set, fruit size and yield were applied to `Fina Sodea' Clementine mandarin in July 2001. Fruits were harvested in November 2001. Treatments designed to delay harvest and enhance on-tree fruit storage were applied to `Fina Sodea' Clementine mandarin in October 2001. Fruit samples were taken on a weekly basis for quality analysis in the following three months. Phenological data of new mandarin hybrids was collected in 2001. AFLP marker analysis of 21 date palm cultivars was completed in 2001.

Impacts
The field trials of different mandarins in different locations through out California will provide information for California growers in selecting new cultivars. Experiments on the management and production of Clementine mandarins and new mandarin hybrids will allow California growers to have better returns.

Publications

  • FERGUSON, L., J.A. POSS, S.R. GRATTAN, C.M. GRIEVE, D. WANG, C. WWILSON T.J. DONOVAN, and C.T. CHAO. 2002. Pistachio rootstocks influence scion growth and ion relations under salinity and boron stress. J. Amer. Soc. Hort. Sci. 127: 194-199.
  • CAO, B.R. and C.T. CHAO. 2002. Identification of date palm cultivars in California using AFLP markers. HortScience (in press)
  • FERGUSON, L., M.L. ARPAIA, T. CHAO, H. REYES, and P. METHENEY. 2001. Current Field evaluations of mandarin cultivars for California (part I). Citrograph v.86 (2): 6 & 10.
  • FERGUSON, L., M.L. ARPAIA, T. CHAO, H. REYES, and P. METHENEY. 2001. Current field evaluations of mandarin cultivars for California (part II). Citrograph v.86 (3): 8-11.
  • FERGUSON, L., M.L. ARPAIA, C.T. CHAO, H. HERACLIO, and P. METHENY. 2001. Performance of Satsuma mandarin in central valley. California Grower v.25(4): 19 & 22.
  • CHAO, C.T., G. WRIGHT, and T. BATKIN. 2001. Citrus industry in China, current status, and future development. Citrograph v.86: 5-6 & 10
  • CAO, B.Y. and C.T. CHAO.. 2001. Identification of date (Phoenix dactylifera) varieties in California by AFLP markers. American Society of Horticultural Science Annual Meeting. HortScience 36(3): 535, poster #63.


Progress 01/02/00 to 12/31/00

Outputs
Study of the genetic control of resistance in avocado rootstocks using half-sib analysis of open pollinated families showed that the narrow sense heritability ranges from 0.13 to 0.73 depending on the half-sib family used in the study. The results indicate that resistant materials should be included in the breeding efforts and large progeny should be screened for highly resistant progeny. Initial AFLP marker typing of PHYTOPHTHORA CINNAMOMI isolates of avocado from California showed some isolates are more similar to P. CINNAMOMI isolates of walnut, blueberry, and oak based on UPGMA analysis of AFLP polymorphism. Field trials of Clementine mandarins, new Satsuma mandarins, and new mandarin hybrid cultivars are underway in multiple locations through out California since 2000. Planting of these new trials will continue through 2002. Evaluation of some trials will begin in fall 2001. Study of management and production strategies for new mandarin hybrids and Clementine mandarins in California started in 2000. Treatments designed for delaying harvesting and enhancing on-tree fruit storage were applied onto `Fina Sodea' Clementine mandarin in November 2000. Fruits from the treatments were collected and the fruit quality characters were evaluated since January 2000. Phenological characters of new mandarin hybrids will be collected beginning in spring 2001. Experiments for increasing fruit set and fruit size of Clementine mandarins will start in spring 2001.

Impacts
The avocado Phytophthora root rot study will gain insight of the host-parasite interactions between PHYTOPHTHORA CINNAMOMI and avocado rootstocks. It will help us to develop strategies to manage Phytophthora root rot of avocado worldwide. The field trials of different mandarins in different locations through out California will provide information for California growers in selecting new cultivars. Experiments on the management and production of Clementine mandarins and new mandarin hybrids will allow California growers to have better returns.

Publications

  • Chao, C.T., McKee, B.S., Guillement, F.B., and Menge, J.A. 2000. Inheritance of Resistance in Avocado Rootstocks against Phytophthora Root Rot. Proceedings of the IV World Avocado Congress v.2. In press.
  • Chao, C.T. 2001. California Citrus Industry - Transition into the Future. Proceedings of the VIV International Society of Citriculture Congress. In press.


Progress 01/01/99 to 12/31/99

Outputs
DNA has been isolated from different isolates of Phytophthora cinnamomi of avocado, walnut, oak, and blueberry. AFLP markers have been applied to avocado Phytophthora root rot isolates. Polymorphic AFLP markers have been identified among Phytophthora root rot isolates of avocado. These polymorphic markers can potentially be used to differentiate different isolates of Phytophthora root rot of avocado. More primer sets are being tested on different Phytophthora cinnamomi isolates. Field trial of new mandarin hybrids in Coachella valley is being set up. Trees will go into ground in March 2000. This trial will study the economic return, production, effect of high density planting, and different management strategies of these new mandarin hybrids in California desert growing area. Another production trial of new citrus cultivars for San Joaquin valley also was initiated. Trees are being propagated. Trees will go into the ground in 2001.

Impacts
The project is in the beginning stages. No significant impact yet.

Publications

  • No publications reported this period