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Results and Discussion

Days to heading in wheat seems to be a quantitative character. Such characters are controlled by a number of major and minor genes separately and collectively. These genes are different in their nature and action. Observations recorded on days to heading revealed the involvement of monosomics 2B, 3B, 5B, 3D and 6D. Of these, monosomics 2B, 3B, and 6D were late while 5B was early as compared to the disomic at the p<0.01. Monosomic 3D, when compared to the disomics, was late at the p<0.05 (
Table 1). All of these chromosomes except 5B have been reported by previous workers to be involved in influencing heading time. According to Yoshida and Kawaguchi (1984), who worked on the monosomics of "Chinese Spring", monosomics 2B, 3B, 6B, 7B, 3D and 6D were involved in days to heading. Of these only 3D was early while the rest were late. Bhat and Goud (1979) worked on the monosomic lines of cv. "Pb. C591" and "UP. 301" and found the effect of chromosomes 5A, 7A, 3D and 7D on heading time. Of these monosomics 7A, 3D and 7D were early while 5A was late. Results reported by Goud and Sridevi (1988) showed that monosomics 1A, 4A, 5A, 6A, 3B, 2D and 7D carry the genes for days to heading in the cultivar "DWR. 39". Of these 6A and 7D were early while the others were late. They, in another report, (Sridevi and Goud, 1988) found the influence of chromosomes 4A, 5A, 2B and 6B in the trisomics of Triticum durum cv. HD. 4502. All of these trisomics were late. Thus the results reported by us are in confirmation with those reported by earlier workers except for monosomic 5B which is being reported here to be involved in heading time.

The mean flag leaf lengths of the monosomics were compared to that of disomics. In the monosomics 1A, 2A, 5A, 6A, 2B, 3B, 4B, 5B, and 6D, the deviations were found to be statistically different as compared to the disomics. Monosomics 5A, 3B and 5B were different at p<0.05 as compared to the disomic while the rest were different at p<0.01. The length of the flag leaf was increased in monosomics 1A, 2A, 5A, 6A, 2B, 3B and 4B while in the remaining two monosomics, i. e., 5B and 6D, it was reduced. Out of the above reported chromosomes, 2A, 2B, 3B and 5B have also been reported to influence the length of flag leaf by Sridevi et al (1989).

As far as the width of flag leaf is concerned, monosomics 1A, 2A, 3A, 3B, 4B, 6D, and 7D were found to affect this character. Of these the width of the flag leaf was decreased in monosomics 6D and 7D while in the others it was increased (
Table 1). The involvement of monosomics 2A and 3A was also reported by Sridevi et al (1989). Besides these two chromosomes, they found the effect of 6A, 1B, 2B, 7B, ID, and 5D on the width of flag leaf. According to them, the flag leaf width was decreased in 5D while in the others it was increased. Chromosomes 1A, 2A, 3B, 4B, and 6D were involved both in flag leaf length and width and thus show greater contribution to flag leaf size. Some differences have thus been observed between our results and those of Sridevi et al (1989) as far as flag leaf size is concerned. Out of the eleven chromosomes shown by us to effect this chracter, six, viz., 1A, 5A, 6A, 4B, 6D and 7D have not been reported by them, although the homoelogues of 1A (1B and ID), 5A (5B and 5D) and 7D (7B) have been shown by them to influence this character. The reason for this discrepancy could be due to the different cultivars used.

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