Abstract
Light and fluorescence microscopy were used to study coenocytic microspore germination from male-sterile (ms1 ms1) soybean plants. Anther squashes from male-sterile plants revealed that a low frequency of natural coenocytic microspore germination occurred in male-sterile anthers of four independent lines; [ms1-North carolina (T260H),ms1-Urbana (T266H),ms1-Tonica (T267H), andms1-Ames (T268H)]. Abnormalities such as giant tubes, branched tubes, tubes with swollen areas, and multiple tubes were observed from coenocytic microspores from all four lines. The Urbana line, however, demonstrated a higher percentage of coenocytic microspore germination than did the other three lines. Flowers of the Urbana line from both malefertile and male-sterile plants, as well as gynoecia pollinated with coenocytic microspores from sterile plants, were used for in vivo studies. Pollen-tube growth appeared normal in male-fertile plants. In contrast, coenocytic microspore tubes rarely were observed in gynoecia from male-sterile plants or in gynoecia from malefertile plants that had been artificially cross-pollinated withms1 ms1 plants. Few tubes from coenocytic microspores were observed in the vicinity of the micropylar region. A low frequency of seed set was achieved in the greenhouse on Urbana male-sterile plants grown in the absence of male-fertile plants. Thus, we believe either that some gametes from coenocytic microspores are able to participate in fertilization at low frequency or that apomixis occurs inms1 ms1 plants.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call