Five cycles of recurrent selection for increased essential oil content in East Indian lemongrass: response to selection, and effects on heritabilities of traits and intertrait correlations

The response of barley composite cross XLII to selection for resistance to powdery mildew was evaluated. Representative samples from eight cycles of recurrent selection were inoculated with two isolates of Erysiphe graminis f.sp. hordei. Frequencies of resistant plants were determined for each cycle. The resistance in composite cross XLII increased with selection. Increased selection pressure in 1986 resulted in a more rapid increase in resistance than in previous years. Multiple alleles occurring in the Ml-a locus did not seem to have a negative effect on the accumulation of resistance in composite cross XLII. Key words: Hordeum vulgare, barley, Erysiphe graminis f.sp. hordei, powdery mildew, response to selection, recurrent selection.

Download Full-text

Selection for Oil Content in East Indian Lemongrass

Plant Breeding ◽

10.1111/j.1439-0523.1986.tb01305.x ◽

1986 ◽

Vol 97 (1) ◽

pp. 78-81 ◽

Cited By ~ 4

Author(s):

R. N. Kulkarni ◽

K. Rajagopal ◽

S. Ramesh

Keyword(s):

Oil Content ◽

East Indian ◽

Selection For

Download Full-text

Recurrent selection for grazing tolerance in winter-active populations of the perennial grass, Phalaris aquatica L.

NZGA: Research and Practice Series ◽

10.33584/rps.12.2006.3041 ◽

2006 ◽

Vol 12 ◽

pp. 89-92

Author(s):

Richard Culvenor ◽

Suzanne Boschma ◽

Kevin Reed

Keyword(s):

Recurrent Selection ◽

Perennial Grass ◽

Grazing Pressure ◽

Soil Conditions ◽

Environment Interaction ◽

Response To Selection ◽

North West ◽

Phalaris Aquatica ◽

Eastern Australia ◽

Selection For

Phalaris (Phalaris aquatica L.) is a perennial grass of Mediterranean origin used widely by the sheep and cattle industries of south-eastern Australia. Winter-active cultivars released since the 1970's have the potential for higher herbage productivity than the earlier, semi-winter dormant cultivars but have been reported to be less persistent under sub-optimal grazing management and soil conditions. To improve genetic potential for persistence in winter-active phalaris, a program of recurrent selection was conducted by subjecting three populations of half-sib families to two cycles of selection for persistence under heavy, largely continuous grazing pressure. Cycle 2 progeny families and bulked seedlots of each generation were grown in separate grazed plot trials in Western Victoria and the Southern Tablelands and North-West Slopes of New South Wales from 1999-2003 to assess response to selection. Positive linear response to selection was observed in all populations at the Western Victorian and Southern Tablelands sites. Response to selection was absent and persistence was very low under higher temperature and drought stress on the North-West Slopes. This high level of genotype Ã— environment interaction for persistence was also observed among final generation families. Families with better persistence than current winteractive cultivars at the two southern sites were identified in each population and a new cultivar is being formed from the parents.

Download Full-text