As revealed by the Table 2, variety Kundan produced 43.3 seeds per spike while p-mst produced only 6.5 seeds per spike. It clearly indicated the stability of male-sterility. All the F₁ hybrids on the other hand produced 45.1 seeds per spike, comparable to fully fertile parent variety Kundan, demonstrating the dominance of fertility trait over the sterility. In the F₂ generation, a segregation ratio of 3 fertile and 1 sterile was observed (Table 2).

On the basis of these observations it is suggested that the male-sterility trait in p-mst strain, is controlled by a recessive gene. In the past, the control of genie male-sterility by single recessive genes has been reported by Pugsley and Oram (1959), Latypov (1974), Driscoll and Barlow (1976), Kleijer and Fossati (1976), Jan and Qualset (1977) and Sasakuma et al. (1978).

The aneuploid analysis of genie male-sterility in p-mst has revealed the involvement of two recessive genes located on chromosomes 4A and 6B (Singh unpub). The variation in the results thus could be due to the use of variable parents in the studies. In the present study the p-mst was crossed with a recently released Indian hexaploid wheat var. Kundan while in the aneuploid study cv. Chinese Spring and its monosomic lines were used. It is, therefore, likely that for normal anther development var. Kundan carry one gene (located on chromosome 4A) while cv. Chinese Spring carry two genes (on 4A and 6B) respectively. The gene located on chromosome 6B in var. Kundan may be in recessive form.

Wheat, basically a self-pollinated crop, exhibits 30-70% positive mid-parent heterosis for grain yield. Thus development of hybrid wheat is in the priority areas of modern agriculture. The p-mst under report is easy to maintain (10-12% selfed seeds), easily transferrable (simple inheritance), least damage from rust diseases (it possesses rust resistances from rye genome) expected enhanced cross pollination (the outer glume of the florets are forced to remain open by the modified ovaries), no adverse effect on female fertility. It may, therefore, serve as an additional tool to develop wheat hybrids.

References

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Jan CC and Qualset CO (1977) Genetic male sterility in wheat: Inheritance. Crop Sci 17: 791-794.

Kleijer G and Fossati A (1976) Chromosomal location of a gene for male sterility in wheat (Triticum aestivum). Wheat Inf Serv 41-42: 12-13.

Krupnov VA (1968) Genic male sterility in common wheat. Genetica 4: 28-35.

Latypov AZ (1974) Digenic nature of male sterile mutants of winter wheat. Sb Nauch Tr Belovrus Acad USSR 123:3-7.

Lemekh IM, PavIishin MM and Savits" kas EV (1971) Some biological characters of pollen sterile plants of Triticum aestivum in relation to their use for breeding. Nauk Pratsi Zemle Robstva Tvarmnitstva Zakhidn USSR 17: 220- 225.

Lupton FGH and Bingham J (1966-67) Winter wheat. In: Plant Breed. Inst, Cambridge Annu Rep: 67.

Pugsley AT and Oram RN (1959) Genic male sterility in wheat. Aust Plant Breed Genet Newslett 14: 10-11.

Sasakuma T, Mann SS and Williams ND (1978) EMS-induced male sterile mutants in euplasmic and alloplasmic wheat. Crop Sci 18:850-853.