1Division of Genetics, IARI, New Delhi, 110 012.
2IARI, Regional Station, Wellington, The Nilgiris, T.N.
WR95, an elite wheat genetic stock has been registered as unique germplasm by the Plant Germplasm Registration Committee of National Bureau of Plant Genetic Resources on the recommendation of the Indian Council of Agricultural Research vide registration number INGR: 08070 (IC 563970). For a successful wheat breeding programme, it is essential to search the germplasm for novel genetic variability and its judicious utilization. Knowledge about the nature and number of genes characterizing various traits in wheat is most desirable for wheat improvement. Therefore, the generation of knowledge about new genes, their mode of inheritance and utility will always remain an area of research. Genetic markers are used in preparing linkage maps which are valuable tools for basic studies. Only a few morphological, cytological and biochemical markers linked to the traits of interest are available in wheat.
WR95, a spring wheat (Triticum aestivum L.) is derived from the cross Kalyansona/Gigas//HD1999/Sonalika/3/T. carthlicum. Investigations were carried out to determine the nature and number of genes governing apical lethality (apical death) in a number of intervarietal crosses of wheat. Genetic analysis of data in segregating generations of the cross WR95/HW2041 and its reciprocal cross revealed that WR95 carries a recessive gene that leads to the death of certain individuals when combined with another recessive gene derived from HW2041. The phenomenon of apical lethality is controlled by two complementary recessive genes coming together from two different parents in certain F2 individuals. The gene symbol apd1 in WR95 and apd2 in HW2041 have been proposed. The gene apd2 is widely distributed in hexaploid wheats, whereas apd1 is confined to only WR95.
In addition to the presence of apd1 gene in WR95, it showed resistance to yellow rust and possesses high grain number/main spike as compared to check variety WH147 as per the report on Genetic Resources published by DWR during 1990 to 1995. Its ear size is large with lax density of spikelets, pubescent glumes which are brown in colour. Anthocyanin pigmentation is absent in coleoptile and leaf sheath auricle at flag leaf stage. WR95 produces light green foliage colour, however, leaf sheath produce small amount of wax.The average plant height is 88 cm having thick culm and leaves. This genetic stock matures in about 122 days, produces amber, semi-hard grains with angular cheeks and wider crease width. The thousand grain weight is about 32 g.
