Soybean Genetics Newsletter: Volume 3, Issue 1
The fact that ms1ms1 plants in maturity ranges I to V were producing haploids, triploids, and even higher ploidy levels along with the predominant normal diploids, indicated the female gametophyte was at least occasionally functioning abnormally. Histological sections of 92 male sterile pistils from plants about Groups III and IV, indicated only about 28% of the ovules had a normal embryo sac, by our interpretation. The remainder most commonly had extra nuclei in the regions of the secondary nucleus (endosperm mother cell) and/or the egg apparatus.
In 1975 we reported the ratio of normal pollen grains to coenocytic pollen grains per anther locule of greenhouse grown plants from the original North Carolina line of the ms1 mutant. The observed ratio was 2:1 rather than the expected 4:1 (Palmer and Albertsen, 1975). Cooper and Boerma (1975), working with the Urbana male sterile, and Palmer and Winger (1975), working with Ames, Harosoy, and Urbana male steriles, proposed that the gene(s) conditioning male sterility are located at the same locus as the ms1 gene.
Forty soybean cultivars were received from the Peoples Republic of China in a number of exchanges between June 1973 and June 1974. The first eight cultivars that we received were grown in row tests at Harrow, Woodslee and Ridgetown in 1975, along with 'Harlen,' 'Harosoy 63,' and 'Harcar.' These eight, plus the next seven that we received, had been tested in hill plots at Harrow in 1974, along with Hardome, Harlen, Harosoy 63, and 'Harwood.' The highest and lowest cultivar values are given for each of a number of characteristics within each group of cultivars as an indication of the potential value of the new germplasm.