A Study on the Effects of Combining Genes from Lonren and Barbren on Reniform Resistance

Upland cotton germplasm lines LONREN and BARBREN-713 are primary sources of host resistance to reniform nematode. Resistance derived from LONREN has been associated with stunting, while resistance genes provided by BARBREN-713 have not been associated with stunting. Lines representing all possible combinations of three major resistance genes from LONREN and BARBREN-713 were developed to compare effects of different gene combinations on reniform resistance and agronomic performance. Using marker assisted selection, two populations (families) with genoytpes representative of all LONREN and BARBREN-713 resistance gene combinations were identified and grown in the greenhouse and winter nursery for seed increase. Six seed of each genotype x population were planted in a growth chamber trial and inoculated at two levels, 0 and 5000 reniform nematodes/120cc of soil. After 60 days, root and shoot weights were taken and nematode reproduction was measured to compare the effects of gene combinations on reniform nematode resistance and stunting.