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Registration of Two Wheat Streak Mosaic Virus‐Resistant Wheat Germplasms
Author(s) -
Sebesta E. E.,
Young H. C.,
Porter D. R.,
Webster J. A.
Publication year - 1995
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1995.0011183x003500040103x
Subject(s) - germplasm , crop , biology , horticulture , library science , agronomy , computer science
derived from BCiFi population to generate BC2Fi population, which, in turn, was backcrossed with the C2 bulk of NC to produce the BC3Fi population. Forty-one dwarf F5 progenies selected for high grain yield by bulk pedigree breeding in the BC3Fi population were random mated for two generations to develop NCD2. For the initial cross (GAM 73 x NC), as well as for the three subsequent backcrosses, bulk pollen of >200 plants was used to represent the recurrent population. The dwarf plants used as females in crosses were selected visually for high grain yield potential, long panicles, and maturity characteristics typical of the recurrent population. A yield trial was conducted in 1982 and 1984 at ICRISAT Asia Center and Bhavanisagar in southern India (4). NCD2 had mean grain yield of 2.86 t ha", which was 19% greater than NC and 33% greater than GAM 73. NCD2 had a mean plant height of 1.2 m (61 % of NC), a mean panicle length of 34 cm (3 cm > NC and GAM 73), and took 51 d to 50% flowering (2 d more than NC and 6 d more than GAM 73). NCD2 had a 1000-seed mass of 7.3 g, compared with 7.8 g for NC and 7.0 g for GAM 73. In a field study involving 21 diverse populations and hybrids, including landraces from the hot and dry areas of western Rajasthan (India) and Niger, NCD2 had the highest seedling emergence (77.5%). It also ranked fourth for seedling thermotolerance index (0.77) at soil surface temperatures up to 64°C (3). The NCD2 population has a high level of resistance to downy mildew [caused by Sclerospora graminicola (Sacc.) J. Schrot.]. In a greenhouse inoculation test at ICRISAT Asia Center, NCD2 had 12% disease incidence, compared with 16% for the D2 Composite, an advanced population, and 99% in the susceptible hybrid, NKB 3. Results from 392 testcrosses developed by crossing S0 plants of NCD2 onto 81 Am, a male-sterile line based on the Am source of cytoplasmic-nuclear male sterility (1), indicated that 21.9% of the crosses shed pollen and were male fertile, 36.2% did not shed pollen and were male sterile, and 41.8% segregated for both pollen shed and male sterility. Very few restorers of Am cytoplasm are available in agronomically elite backgrounds. NCD2 provides a useful source from which both restorers and maintainers of the Am cytoplasm could be developed. Seed of NCD2 will be maintained and distributed upon request in germplasm quantities by the Genetic Enhancement Division, ICRISAT Asia Center, Patancheru, Andhra Pradesh, India.