Genetic and Developmental Analysis of Hybrid Necrosis in Wheat

The present investigation was undertaken to study the distribution of necrosis genes in some Indian and exotic varieties of wheat and to determine the cause of this hybrid abnormality. Four Indian varieties, C 303, C 306, G 286 and NP 890 and one American variety Big Club 24 carried the Ne₁ gene. The varieties PV 18, S 385, K 227, S 226, Nadadores 63, Penjamo 62, Sonora 64, and Lerma Rojo of Mexican origin, the variety Kitakamikomugi of Japanese origin and the variety E 5573 of Chilean origin carried the Ne₂ gene. Necrotic hybrids had considerably reduced vigour and in most of the hybrids death of the plants occurred before earing. Hybrid necrosis was due to the death of the chloroplasts and it was not associated with any histological abnormality of stem and root and size and number of stomata.