Biplot analysis of diallel data in strip rust of wheat

Abstract

Five bread wheat cultivars (Kokart, Domino, Ruapuna, Pool, and Tiritea), showing a wide response to yellow rust, were intercrossed in all combinations to provide a F1 half-diallel for assessing disease infection type in Iran. The diallel dataset of the five cultivars was carried out by diallel GGE biplot analyze. The parents and 10 F1 progenies were evaluated in the greenhouse by three pathotypes 7E18A¯, 38E0A+, and 134E134A+. The first two principal components of biplot explained 95, 94 and 85 % of the variation for the pathotypes 7E18A¯, 38E0A+, and 134E134A+, respectively. Ruapuna for the pathotypes 7E18A¯ and 134E134A+, Kokart for the pathotype 38E0A+ had negative general combining ability (GCA) (more resistance) for infection type. Parent Tiritea was the best mating partner with the other parents for the pathotypes 7E18A¯ and 38E0A+ while this parent was the best mating partner only with testers Kokart and Pool for the pathotype 134E134A+. Entry of Kokart was the best mating partner with testers Domino, Ruapuna, and Tiritea in the pathotype 134E134A+. The results showed that parent Ruapuna was good in three combinations of the pathotypes (7E18A¯ + 38E0A+ + 134E134A+, 7E18A¯ and 38E0A+ + 134E134A+) and so had good ability to show resistance by low infection type. Additive genetic component indicate the possibility of improving for resistance to stripe rust with the lower infection type in breeding programs.