Inheritance of shattering in wild rice.

Data from the S1 (parental), F1 and F2 generations of crosses involving five Zizania aquatica ecotypes showing grain shattering and five plants of a nonshattering mutant, which also retained its staminate florets, revealed that shattering was conditioned by two complementary dominant alleles, designated Sh and Sh2, and occurred when at least one dominant allele was present in both loci. Genotypes resistant to shattering were: shsh sh2sh2, shsh Sh2 -, and Sh - sh2sh2. All F2 plants which retained 100% of their staminate florets at the completion of anthesis were classed as resistant, while all those which lost all of their staminate florets were classed as susceptible. Other plants were observed that retained some staminate florets; some of these plants were susceptible and some were resistant to shattering. It is concluded that selection for shattering-resistant plants at anthesis can be accomplished by selecting plants having 100% staminate-floret retention.