| All the three plants were vigorous and produced 58, 64 and 41 ear bearing
tillers respectively and showed excellent field resistance to stem, leaf
and stripe rusts. There were no distinct morphologicai differences among
these hybrids. The hybrid plants were dwarf and had thin stem with prominent
nodes and narrow leaves like T. speltoides. Spikes were lax having
1-4 florets per spikelet. The plants were medium late in maturity. Most
of the spikes were backcrossed to Sonalika and the florets were pollinated
twice. Seed set in different spikes was poor ranging from 0.75% to 6.52%.
II backcroos generation. In the case of 2n = 35 plant a total of 42 seeds were obtained in the crosses but only 35 seeds germinated. The segregants were vigorous in growth, short statured with narrow leaves and thin stem. 80% progenies showed a high degree of adult plant resistance to leaf rust (Puccinia recondita) and high to moderate resistance to stem rust (Puccinia graminis tritici); however, the progenies were found susceptible to stripe rust (Puccinia striiformis). Comparatively seed setting on the hybrid plant 2n = 37 when backcrossed to Sonalika was poor than that obtained in 2n = 35 plant. In this case too, the segregants showed remarkable degree of mature plant resistance to stem and leaf rusts. Similarly, 2n = 39 hybrid plant yielded less number of seeds upon backcrossing, although 2n = 35 plant recorded a high frequency of trivalent formation (0.85/cell) than that of 2n = 39 plant which showed only 0.12 trivalents/cell. However, the type of resistance observed among the progenies of 2n = 39 x Sonalika was as good as observed in other two cases. The progenies were grown under natural infection of all the three rusts obtaining at Wellington. The chromosome constitution of the segregants has not been determined. Further backcrossing and selection work is under progress. Reference SAWHNEY, R.N., S.K. NAYAR, S.D. SINGH & V.L. CHOPRA 1977. Virulence pattern of the Indian leaf rust races on lines and varieties of wheat with known Lr genes. SABRAO J. 9(1): 13-20. |
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