Cytoplasmic Effects on Agronomic and Malting Quality Traits in Barley1

Abstract

The presence of genetic information in organelles of the cytoplasm suggests that certain nucleus‐cytoplasm combinations may be superior in terms of crop productivity or crop quality. The objective of this study was to examine cytoplasmic effects on eight agronomic and seven malting quality traits in six‐rowed malting barley (Hordeum vulgare L.). Backcrossing was used to incorporate the nuclear genome of two malting cultivars, ‘Conquest’ and ‘Dickson’, into six diverse cytoplasms represented by three H. vulgare cultivars and three other Hordeum species. Backcross derived lines and Conquest and Dickson were evaluated in field trials at two Minnesota locations in 1978 and 1983. In all, 15 traits were examined in 12 different nucleus‐cytoplasm combinations. There was little evidence of cytoplasmic effects on the agronomic traits and none for the malting quality traits. The six cytoplasms failed to influence any of the traits in combination with the Conquest nuclear genome. In the Dickson backcrosses, ‘Betzes’ cytoplasm resulted in a slightly earlier heading date, and H. spontaneum var. spontaneum cytoplasm resulted in an earlier heading date and fewer plump kernels. The different performance of the Conquest and Dickson backcross derived lines may indicate a failure to rid the Dickson derived lines of nuclear genes from the cytoplasm donors or be evidence of nuclear‐cytoplasm genotype interaction.