Crucifer Vegetables with Resistance to Blackrot and Alternaria Leaf Spot 1997
Project Leader: Elizabeth D. Earle
1. Continue development of broccoli, cauliflower and cabbage lines with high levels of resistance to blackrot for use in New York State crucifer IPM programs.
a. Screen the most advanced progeny of the resistant plants for seedling and mature plant resistance to blackrot and score them for fertility and horticultural quality.
b. Identify for further use those lines with the highest percentage of resistant progeny and determine whether this stability is related to DNA content and/or chromosome number.
c. Cross the best lines to cauliflower and cabbage to transfer resistance to these crops.
d. Conduct a larger field trial of our most advanced materials at Reed's Seeds (Cortland, NY).
e. Make seeds of lines with stable resistance available to growers and seed companies.
f. Include information about the resistant lines in "Cornell Recommends."
2. Continue work to obtain crucifer vegetable lines with high levels of resistance to Alternaria disease for use in New York State crucifer IPM programs.
a. Test our new somatic hybrids for resistance to Alternaria.
b. Attempt to obtain BC1 progeny from the most resistant hybrids via embryo rescue. Test these progeny for resistance and use them in further crosses.
Single cells from two resistant crucifer species were fused with cells from a rapid-growing Brassica oleracea line. The fused cells were grown into somatic hybrid plants that were resistant to blackrot or to Alternaria. The blackrot-resistant hybrids were repeatedly crossed with broccoli in order to obtain resistant materials suitable for horticultural use. The field test in Cortland identified several lines with stable high resistance to blackrot. Seeds have been collected for release in 1998. Crosses to cabbage have also been done to transfer blackrot resistance into this crop. A similar approach is being used to develop materials with enhanced resistance to Alternaria disease. Difficulties in obtaining seeds from the resistant somatic hybrids have been overcome, and an additional generation of progeny is now available for further work.