Deptt. of Plant Breeding, G. B. Pant University of Agriculture and Tech., Pantnagar, Distt. Nainital
Online published on 25 January, 2012.
The inheritance of sterility as well as the morphological and cytological abnormalities associated with it were studied in three male lines of soybean viz: Semmes M.S.-l, Semmes M.S.-2 and N 69–2774.
In all the three lines sterility was controlled by single recessive gene pairs. However, the cytological abnormalities and pollen behaviour differed markedly from line to line. There was a complete failure of cytokinesis after telophase II in the sterile plants of N 69–2774 and consequently the 4 daughter nuclei got encapsulated into a single pollen wall resulting into large size (almost double of the normal) multinucleate pollen grains which were non functional. In case of Semmes M.S.–2, normal cytokinesis after telophase II was observed but the 4 daughter nuclei degenerated immediately after that and thus no microspore could be produced. As a result the sterile plants of Semmes M.S. 2 had no pollen at all. The sterile plants of Semmes M.S. 1 showed normal cytokinesis and microspore formation but the pollen development was defective resulting into non functional pollen grains. The size of the sterile pollen, however, was not different than the normal pollen grains.
On an average Semmes M.S. 2 had 33⋅81 pods/sterile plant with 1⋅87 seed/pod as compared to 2⋅28 pods/sterile plant with 1⋅01 seeds/pod in case of Semmes M.S.–l and 14⋅87 pods/sterile plant with 1⋅20 seeds/pods in case N 69–2774. Apparently the sterile plants of Semmes M.S. 2 had maximum female fertility and those of Semmes M.S. 1 the least.
The differential pod set coupled with differential cytological and pollen behaviour of the male sterile plants of Semmes M.S. 1, Semmes M.S. 2 and N 69–2774 suggest that the genes controlling male sterility in these lines are different.
