Inheritance of Shattering in Wild Rice¹

Abstract

Wild rice (Zizania aquatica L.) is a native annual aquatic cereal that grows in lakes and streams in the upper great lakes region of North America. Native ecotypes shed staminate florets shortly after anthesis and grain shatters over a 2 to 3 week maturation period. A mutant was found which retains its staminate florets beyond anthesis and has a moderate degree of resistance to seed shattering. Objectives of this study were to determine the mode of inheritance of shattering resistance and to determine the relationship between staminate floret retention and resistance to seed shattering.Crosses were made between five shattering susceptible plants and five shattering resistant plants. The resulting S1, F1, and F2 progenies were studied. Two complementary dominant genes were proposed to explain the observed segregations. Susceptibility to shattering occurred when at least one dominate allele (Sh− Sh2−) was present at both loci. Shattering resistant genotypes were: sh sh sh2 sh2, sh sh Sh2−, and Sh− sh2 sh2. 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. The selection of shattering resistant plants at anthesis can be accomplished by selecting plants having 100% staminate floret retention.

High-density AFLP map of nonbrittle rachis 1 (btr1) and 2 (btr2) genes in barley (Hordeum vulgare L.)

“…In wild rice (Zizania spp. ), two complemental genes or three QTLs control seed dispersal (Elliott and Perlinger 1977;Kennard et al 2002). Furthermore, ten QTLs have been identified in maize (Paterson et al 1995).…”

Genetic dissection of seed shattering, agronomic, and color traits in American wildrice (Zizania palustris var. interior L.) with a comparative map

“…Simple inheritance conditioned by one or two dominant genes has been proposed to describe the inheritance of seed shattering (Woods and Clark 1976;Elliott and Perlinger 1977). Observations of 3:1 and 9:7 F 2 segregation ratios provided evidence for a two-complementary dominant-gene system to control shattering (Elliott and Perlinger 1977).…”

“…Observations of 3:1 and 9:7 F 2 segregation ratios provided evidence for a two-complementary dominant-gene system to control shattering (Elliott and Perlinger 1977). The model consists of A_ B_genotypes that condition shattering phenotypes, and aa B_, A_bb and aa bb, genotypes that condition non-shattering phenotypes.…”

Wild rice - a potential new crop for Finland

“…A breeding programme to develop non-shattering cultivars was conducted at the University of Minnesota in an attempt to reduce losses due to shattering. Elliott and Perlinger (1977) worked with a wild rice mutant that did not shed its staminate florets and had only a moderate degree of seed shattering. Later work by Everett and Stucker (1983) confirmed that shattering is the dominant trait of the recessive two-complementary-gene system, a finding that explains the good results obtained…”