Source: UNIVERSITY OF CALIFORNIA submitted to
GENETICS AND BREEDING OF ASPARAGUS
Sponsoring Institution
State Agricultural Experiment Station
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0151029
Grant No.
(N/A)
Project No.
CA-R*-BPS-5200
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Oct 1, 1999
Project End Date
Sep 30, 2005
Grant Year
(N/A)
Project Director
Roose, M. L.
Recipient Organization
UNIVERSITY OF CALIFORNIA
(N/A)
RIVERSIDE,CA 92521
Performing Department
BOTANY AND PLANT SCIENCES
Non Technical Summary
(N/A)
Animal Health Component
50%
Research Effort Categories
Basic
10%
Applied
50%
Developmental
40%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2021430108020%
2031430108040%
2121430108040%
Goals / Objectives
1)Develop new hybrids, evaluate their adaptation, yield, and quality, and develop methods to produce virus-free seed. 2) Develop genetic markers to identify cultivars and select parents. 3) Assess genetic diversity and develop a broad germplasm base for future cultivar development. 4) Determine the moe of inheritance of important traits. 5) Obtain Fusarium and Phytophthora resistant genotypes and use to develop resistant cultivars.
Project Methods
1) Promising hybrid cultivars will be evaluated for growth, yield, disease resistance, and spear quality in replicated multilocation trials in Riverside, the San Joaquin Valley, and perhaps other areas. These trials will be conducted in cooperation with local farm advisors and growers. At least 200 new hybrids will be produced and entered in unreplicated trials at Riverside. All-male hybrids will be generated using supermales from selfing hermaphrodite plants or derived from anther culture. Methods for micropropagation of selected male and female parents will be identified by testing various explant sources, cultue media, environmental conditions. PCR-based tests to detect AV2 will be developed by designing primers from published sequences and evaluating these for detection of various viral strains. Only AV2-free plants will be used for seed production.

Progress 10/01/99 to 09/30/05

Outputs
To develop new, more productive asparagus cultivars for California, new cultivars were developed by hybridization and selection and evaluated in a series of field trials. New and existing cultivars were compared in five field trials planted in Riverside from 2000-2004. Several hybrid cultivars that have M256 as their male parent are very promising in all trials conducted to date, having higher yields than UC157 and the hybrids evaluated in the earlier trials. The more promising of these hybrids are now being evaluated in the San Joaquin Delta area. We micropropagated the parents of one such hybrid, line UC115, and these were used to establish the first seed production fields. Commercial release is expected in late 2005 or early in 2006. The cultivars discussed above are of mixed sex. All-male cultivars are often higher yielding than mixed-sex cultivars and can be developed by crossing rare 'supermale' plants with normal females. Previous results showed that some all-male hybrids have superior total yield to the other varieties tested, but none of them had acceptable spear quality. Trials to evaluate new all-male hybrids were planted from 2001 to 2003, and results from the 2003 trial have been promising with many new hybrids having high yield and good spear quality. In a trial to evaluate various cultural practices, as in previous years, plots treated with compost had slightly higher yields, and were significantly earlier, but had lower stands than untreated plots. Total marketable yield of UC157-F2 was only 33% that of UC157-F1, indicating considerable advantage from use of F1 seed of this cultivar. To evaluate asparagus varieties from a wide variety of production areas and expand the genetic base of the breeding program we planted a trial of 38 diverse cultivars in 2002. This trial is part of the Third International Asparagus Cultivar Trial. Stand and vigor were excellent in 2004 and 2005. This trial was harvested for the first time in 2004, with each plot harvested for at least seven weeks, and for a full season in 2005. The highest marketable and export yields were from UC115 and NJ953. Although NJ953 had higher total yield, UC115 had significantly higher export quality spears and percent marketable yield. Atlas also had high marketable yield, but most spears were too large for export quality. Early lines included DePaoli, NJ1019, NJ956, UC115, and NJ953. A trial planted in 2003 to evaluate new hybrids had excellent stands and good yields. Based on the first year's data, some male hybrids had yields and quality approaching those of the best mixed-sex hybrids. No new trials were planted. A project to map genes that determine sex, spear quality, and other traits was completed. AFLP markers are being used to develop linkage maps and a replicated planting of about 150 different clones will be used to measure spear quality, yield and other traits. The asparagus breeding project will be continued, but included in a new revision of project CA-R*-BPS-4242H.

Impacts
Development of new, more productive asparagus cultivars will benefit growers and shippers by making the California industry more competitive. Consumers may be provided with fresh asparagus at lower cost.

Publications

  • No publications reported this period


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

Outputs
To develop new, more productive asparagus cultivars for California, new cultivars were developed by hybridization and selection and evaluated in a series of field trials. New and existing cultivars were compared in five field trials planted in Riverside from 2000-2003. Several hybrid cultivars that have M256 as their male parent are very promising in all trials conducted to date, having higher yields than UC157 and the hybrids evaluated in the earlier trials. The more promising of these hybrids are now being evaluated in the San Joaquin Delta area. We micropropagated the parents of one such hybrid, line UC115, and these were used to establish the first seed production fields. Commercial release is expected in late 2005. The cultivars discussed above are of mixed sex. All-male cultivars are often higher yielding than mixed-sex cultivars and can be developed by crossing rare "supermale" plants with normal females. Previous results showed that some all-male hybrids have superior total yield to the other varieties tested, but none of them had acceptable spear quality. Trials to evaluate new all-male hybrids were planted from 2001 to 2003. In a trial to evaluate various cultural practices, as in previous years, plots treated with compost had slightly higher yields, and were significantly earlier, but had lower stands than untreated plots. Total marketable yield of UC157-F2 was only 33% that of UC157-F1, indicating considerable advantage from use of F1 seed of this cultivar. To evaluate asparagus varieties from a wide variety of production areas and expand the genetic base of the breeding program we planted a trial of 38 diverse cultivars in 2002. This trial is part of the Third International Asparagus Cultivar Trial. Stand and vigor were excellent in 2004. This trial was harvested for the first time in 2004, with each plot harvested for at least seven weeks. The highest marketable and export yields were from UC115. Atlas also had high marketable yield, but most spears were too large for export quality. Surprisingly, Pacific Purple and Purple Passion had the next highest marketable yields, followed by Grande and Plaverd. NJ953, NJ1019, Gijnlim, and Jersey Giant had high total yields, but relatively low marketable yields. Early lines included Ravel, Jersey King, Atlas, NJ1019, NJ956, UC115, and NJ953. A trial planted in 2003 to evaluate new hybrids had excellent stands. No new trials were planted. A project to map genes that determine sex, spear quality, and other traits was continued. AFLP markers are being used to develop linkage maps and a replicated planting of about 150 different clones will be used to measure spear quality, yield and other traits.

Impacts
Development of new, more productive asparagus cultivars will benefit growers and shippers by making the California industry more competitive. Consumers may be provided with fresh asparagus at lower cost.

Publications

  • No publications reported this period


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

Outputs
To develop new, more productive asparagus cultivars for California, new cultivars were developed by hybridization and selection and evaluated in a series of field trials. New and existing cultivars were compared in six field trials planted in Riverside from 2000-2002. Several hybrid cultivars that have M256 as their male parent are very promising in all trials conducted to date, having higher yields than UC157 and the hybrids evaluated in the earlier trials. The more promising of these hybrids are now being evaluated in the San Joaquin Delta area. We continued micropropagating the parents of line UC115 to establish large seed production blocks for commercial release of this cultivar. The cultivars discussed above are of mixed sex. All-male cultivars are often higher yielding than mixed-sex cultivars and can be developed by crossing rare "supermale" plants with normal females. Previous results showed that some all-male hybrids have superior total yield to the other varieties tested, but none of them had acceptable spear quality. Trials to evaluate new all-male hybrids were planted from 2001 to 2003. Trials to evaluate rust control chemicals and cultural practices were planted in 2000 and evaluated from 2001 to 2003. The rust control trial was harvested in 2002 and 2003, but overall performance was poor and variation among plots was high so significant differences were not detected. The trial was abandoned after a short harvest season in 2003. In the cultural practices trial, plots treated with compost had slightly higher yields, and were significantly earlier, but had lower stands than untreated plots. Total marketable yield of UC157-F2 was only 56% that of UC157-F1, indicating considerable advantage from use of F1 seed of this cultivar. A 2002 trial was designed to evaluate Phytophthora tolerance of 17 hybrids, including 5 hybrids from New Zealand selected for Phytophthora resistance. Results showed significant differences in survival among lines, but many of the New Zealand lines were susceptible, and Ida Lea, characterized elsewhere as susceptible, appeared quite tolerant. Additional work will be needed to determine whether these unexpected results are due to variation among Phytophthora sources or other environmental factors. To evaluate asparagus varieties from a wide variety of production areas and expand the genetic base of the breeding program we planted a trial of 38 diverse cultivars in 2002. This trial is part of the Third International Asparagus Cultivar Trial. Harvests will begin in 2004. One new trial was planted in 2003 to evaluate new hybrids including six replicate plots of 10 new experimental hybrids from UCR (one all-male hybrid and 9 dioecious hybrids) and six replicate plots of UC157 and UC115. A project to map genes that determine sex, spear quality, and other traits was initiated. AFLP markers are being used to develop linkage maps and a replicated planting of about 150 different clones will be used to measure spear quality, yield and other traits.

Impacts
Development of new, more productive asparagus cultivars will benefit growers and shippers by making the California industry more competitive. Consumers may be provided with fresh asparagus at lower cost.

Publications

  • No publications reported this period


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

Outputs
To develop new, more productive asparagus cultivars for California, new cultivars were developed by hybridization and selection and evaluated in a series of field trials. New and existing cultivars were compared in field trials planted in Riverside in 1995 and 2000. Since 1996, spears have been graded into domestic and export classes. Several hybrid cultivars that have M256 as their male parent are very promising in all trials conducted to date, having higher yields than UC157 and the hybrids evaluated in the earlier trials. The more promising of these hybrids are now being evaluated in the San Joaquin Delta area. We have begun to micropropagate the parents of line UC115 to establish large seed production blocks for commercial release of this cultivar. The cultivars discussed above are of mixed sex. All-male cultivars are often higher yielding than mixed-sex cultivars and can be developed by crossing rare "supermale" plants with normal females. We used a DNA marker to aid in identification of 39 such supermales. Previous trials of the first selections from this program showed that some all-male hybrids have superior total yield to the other varieties tested, but none of them have commercially acceptable spear quality. A trial to evaluate a new set of all-male hybrids was planted in 2001, but this will not be harvested until 2003. New trials to evaluate rust control chemicals and cultural practices were planted in 2000 and evaluated in 2001 and 2002. The first, limited harvest of the rust control trial was made in 2002. It was notable that all 5 chemical control treatments had higher marketable yields (162-297 lb/ac) than the control (120 lb/ac), but there were no significant differences between lines or among the treatments, perhaps due to high variation among plots with a short harvest season. In the cultural practices trial, plots treated with compost had lower yields and stand than untreated plots and total marketable yield of UC157-F2 was about 25% lower than that of UC157-F1, but differences were not statistically significant. Three new trials were planted in 2002. One is a replicated trial of 19 experimental hybrids (6 all-male) and 5 hybrids obtained from New Zealand. Unreplicated plots of 26 new hybrids were also planted. Many of these hybrids include selections from backcrossing European germplasm with California materials. Another new trial will evaluate Phytophthora tolerance of 17 hybrids, including 5 hybrids from New Zealand selected for Phytophthora resistance. To evaluate asparagus varieties from a wide variety of production areas and expand the genetic base of the breeding program we also planted a trial of 38 diverse cultivars as part of the Third International Asparagus Cultivar Trial. A new RT-PCR test to detect Asparagus Ilarvirus showed that micropropagated parent clones of UC115 were free of Asparagus Ilarvirus 2. Interspecific hybrids with species having rust, Stemphyllium and salinity tolerance were obtained from Dr. Falavigna in Italy and analysis of recombination in these materials was begun.

Impacts
Development of new, more productive asparagus cultivars will benefit growers and shippers by making the California industry more competitive. Consumers may be provided with fresh asparagus at lower cost.

Publications

  • Stone, N.K and Roose, M.L. 2002. Effective field evaluation of asparagus hybrids using reduced data collection. Acta Horticulturae 589:103-109.
  • Roose, M.L, Stone N.K., Mathews, D.M., and Dodds, J.A. 2002. RT-PCR detection of asparagus 2 Ilarvirus. Acta Horticulturae 589:357-363.


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

Outputs
In order to develop new, more productive asparagus cultivars for California, new cultivars were developed by hybridization and selection and evaluated in a series of field trials. New and existing cultivars were compared in field trials planted in Riverside in 1995 and 1998. Since 1996, spears have been graded into domestic and export classes. Several hybrid cultivars that have M256 as their male parent are very promising in all trials conducted to date. Many of these hybrids had higher yields than UC157 and the hybrids evaluated in the earlier trials. The more promising of these hybrids are now being evaluated in the San Joaquin Delta area, and we hope to release one new cultivar in 2002. All of the cultivars discussed above are of mixed sex. All-male cultivars are often higher yielding than mixed-sex cultivars and can be developed by crossing rare "supermale" plants with normal females. We used a DNA marker to aid in identification of 39 such supermales. Previous trials of the first selections from this program showed that some all-male hybrids have superior total yield to the other varieties tested, but none of them have commercially acceptable spear quality. Considerable selection among the supermale parents will be necessary to develop all-male cultivars with acceptable spear quality. A trial to evaluate a new set of all-male hybrids was planted in 2001. A 1998 trial to develop procedures for Phytophthora resistance testing was harvested for the second time in 2001. Plots treated with Ridomil had substantially higher yields than untreated plots, indicating that Phytophthora stress was present, but there were no significant differences in resistance among the 4 lines compared. Future trials should include more replication and more efficient methods to apply fungicide to control plots. New trials to evaluate rust control chemicals and cultural practices were planted in 2000 and evaluated in 2001. In the rust control trials, the overall level of rust was too low and we plan to increase the frequency of overhead irrigation in future years to encourage more rust development. In 2001 we planted a new trial to evaluate hybrids in the presence of high rust pressure. To expand the germplasm base of our program, we evaluated yield and quality of 1440 single plants from backcrosses of California x European hybrids and selected 13 clones, which have high yields of export-quality spears. F1 hybrids involving these selected clones were planted in a new trial in 2001 to evaluate the selected clones as parents of new cultivars. We continued to develop a new test to detect asparagus virus II so that virus-free asparagus seed can be produced.

Impacts
Development of new, more productive asparagus cultivars will benefit growers and shippers by making the California industry more competitive. Consumers may be provided with fresh asparagus at lower cost.

Publications

  • No publications reported this period


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

Outputs
In order to develop new, more productive asparagus cultivars for California, new cultivars were developed by hybridization and selection and evaluated in a series of field trials. New and existing cultivars were compared in field trials planted in Riverside in 1994, 1995, 1996, and 1998. Since 1996, spears have been graded into domestic and export classes. Several hybrid cultivars that have M256 as their male parent are very promising in the 1994 and 1995 trials. Many of these hybrids had higher yields than UC157 and the hybrids evaluated in the earlier trials. The more promising of these hybrids are now being evaluated in the San Joaquin Delta area. All of the cultivars discussed above are of mixed sex. All-male cultivars are often higher yielding than mixed-sex cultivars and can be developed by crossing rare "supermale" plants with normal females. We used a DNA marker to aid in identification of 39 such supermales. The 1995 and 1996 trials include the first selections from this program. Some of these all-male hybrids have superior total yield to the other varieties tested, but none of them have spear quality as good as that of UC157. Considerable selection among the supermale parents will be necessary to develop all-male cultivars with acceptable spear quality. A 1998 trial to develop procedures for Phytophthora resistance testing was harvested for the first time in 2000. Plots treated with Ridomil had substantially higher yields than untreated plots, indicating that Phytophthora stress was present. There were no significant differences in resistance among the 5 lines compared. New trials to evaluate rust control chemicals and cultural practices were planted in 2000. To expand the germplasm base of our program, we selected clones which have high yields of export-quality spears from a cross between F109 (the female parent of UC157) and two California x European hybrids. These will be evaluated as parents of new cultivars. A screenhouse to produce larger amounts of experimental seed was built in 1998 and the first seed was produced this year. We continued to develop a new test to detect asparagus virus II so that virus-free asparagus seed can be produced. This test gave unexpected results that are difficult to interpret, but might indicate the presence of a previously undetected virus. Release of new cultivars should occur when trials to characterize performance in larger plots in the San Joaquin Delta have been completed.

Impacts
Development of new, more productive asparagus cultivars will benefit growers and shippers by making the California industry more competitive. Consumers may be provided with fresh asparagus at lower cost.

Publications

  • No publications reported this period


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

Outputs
In order to develop new, more productive asparagus cultivars for California, new cultivars were developed by hybridization and selection and evaluated in a series of field trials. New and existing cultivars were compared in field trials planted in Riverside in 1994, 1995 and 1996. Since 1996, spears have been graded into domestic and export classes. Several hybrid cultivars that have M256 as their male parent are very promising in the 1994 and 1995 trials. Many of these hybrids had higher yields than UC157 and the hybrids evaluated in the earlier trials. The more promising of these hybrids are now being evaluated in the San Joaquin Delta area. All of the cultivars discussed above are of mixed sex. All-male cultivars are often higher yielding than mixed-sex cultivars and can be developed by crossing rare "supermale" plants with normal females. We used a DNA marker to aid in identification of 39 such supermales. The 1995 and 1996 trials include the first selections from this program. Some of these all-male hybrids have superior yield to the other varieties tested, but none of them have spear quality as good as that of UC157. Considerable selection among the supermale parents will be necessary to develop all-male cultivars with acceptable spear quality. Harvesting trials is a major limitation in the breeding program because each trial must be harvested and spears weighed and graded three times per week for about 9 weeks. Statistical analysis of multi-year data on three trials showed that superior lines could be identified from data on a single grading per week. Adopting this procedure will substantially improve the efficiency of the trial phase of the breeding program. A new trial to develop procedures for Phytophthora resistance testing was planted in 1998, but it has not been harvested yet. To expand the germplasm base of our program, we selected clones which have high yields of export-quality spears were selected from a cross between F109 (the female parent of UC157) and two California x European hybrids. These will be evaluated as parents of new cultivars. A screenhouse to produce larger amounts of experimental seed was built in 1998 and promising parents have been planted in it. We began to develop a new test to detect asparagus virus II in asparagus tissue. Initial results are quite promising. This test would be used to ensure that asparagus seed is virus-free. Release of new cultivars should occur when trials to characterize performance in larger plots in the San Joaquin Delta have been completed.

Impacts
Development of new, more productive asparagus cultivars will benefit growers and shippers by making the California industry more competitive. Consumers may be provided with fresh asparagus at lower cost.

Publications

  • Roose, M.L. and Stone, N.K. 1999. Genetic and breeding of asparagus at the University of California, Riverside. Acta Horticulturae 479:101-107.
  • Stone, N.K. and Roose, M.L. 1999. Field evaluation of new asparagus varieties at the University of California, Riverside. Acta Horticulturae 479:185-188.


Progress 01/01/95 to 12/30/95

Outputs
In a trial planted in Riverside in 1990, the highest marketable yield for 1995 was produced by `Atlas'. One new UCR line had higher yield that `UC157'. New trials were planted at two locations in Riverside. Several new supermale plants were identified and will be tested as parents for all-male cultivars. We were unsuccessful in an attempt to identify a genetic marker linked to the sex-determining locus. Crosses were made to study inheritance of branching height. Analysis of several seed samples of putative `UC157-F1' with an RFLP marker showed that some seed is mislabeled and some contains many off-types, perhaps due to establishment of hybrid seed in seed production plots.

Impacts
(N/A)

Publications

  • No publications in this reporting period.


Progress 01/01/94 to 12/30/94

Outputs
New hybrids were evaluated for yield and quality in replicated and unreplicated trials in Riverside for 3 years. Some hybrids had higher yield than existing cultivars, but the error variance was high. Evaluation of these hybrids at other locations indicates variable performance and more testing is needed. Initial, unreplicated testing of 107 new hybrids at Riverside suggests that many are promising and these have been planted replicated trials. New supermale parents were developed by selfing andromonoecious plants. Plantlets were derived from anther cultures and may provide additional supermales for evaluation. Molecular marker studies indicate that the germplasm used in the California asparagus breeding program has a relatively narrow genetic base. Additional foreign germplasm was crossed with California germplasm to broaden the genetic base for future breeding and selection. Genetic markers to distinguish between the F1 and F2 generations of the patented cultivar `UC157' were developed.

Impacts
(N/A)

Publications

  • No publications reported this period.


Progress 01/01/93 to 12/30/93

Outputs
Yield and quality were recorded for replicated and unreplicated breeding trials at Riverside. Some new hybrids appear higher yielding than existing cultivars, but error variation is high and continued evaluation at several locations is required before any new cultivars can be released. A trial in the Coachella Valley was terminated after one year of yield records because of severe Fusarium damage. Several cooperative trials in the San Joaquin delta area were evaluated, but performance of many new hybrids was inconsistent across locations. Additional foreign germplasm was crossed with California germplasm to broaden the genetic base of breeding material. Genetic markers to distinguish between the F1 and F2 generations of the patented cultivar `UC157' were developed.

Impacts
(N/A)

Publications

  • ROOSE, M.L. and STONE, N.S. 1993. Development of genetic markers to distinguish between the F1 and F2 generations of asparagus cultivar `UC157'. Acta Horticulturae. 8 pp. In Press.


Progress 01/01/92 to 12/30/92

Outputs
RAPD markers were used to characterize genetic diversity in California asparagusgermplasm and a few foreign cultivars. Diversity in California germplasm was lower than in the foreign cultivars. First year yields of experimental hybrids were not significantly correlated with genetic distance between parents as measured with RAPD analysis, but the power of the test was not strong. Tests of the inheritance of RAPD markers were set up but not completed and final interpretation of the genetic diversity will require completion of these inheritance studies. The first harvest season of a new yield trial at Riverside was completed but several more years will be required before conclusions can be reached. Anther cultures were initiated to produce new supermale parents for future breeding.

Impacts
(N/A)

Publications

  • No publications reported this period.


Progress 01/01/91 to 12/30/91

Outputs
Methods for development of genetic markers using arbitrary primers and polymerase chain reaction (RAPD markers) were developed. Initial results were promising and shown polymorphism but supposed hybrids sometimes had bands not present in either parent. This problem must be solved before these methods can be applied to germplasm or segregating population. Replicated trials at 5 locations were evaluated for fern vigor and rust. Harvesting will begin in 1992.

Impacts
(N/A)

Publications

  • NO PUBLICATIONS REPORTED THIS PERIOD.


Progress 01/01/90 to 12/30/90

Outputs
Isozymes were evaluated as genetic markers to identify cultivars and characterize germplasm, but essentially no variation was found within California germplasm. A genomic DNA library was made and approximately 20 random clones were tested for detection of RFLP variation in California germplasm. No variation was found. Replicated trials were established at 5 locations to evaluate 7 new hybrid lines from the Riverside program, 5 lines from other public and private breeding programs and 3 standard cultivars. An unreplicated trial was planted at UCR to evaluate 100 new hybrids.

Impacts
(N/A)

Publications

  • No publications reported this period.