Male Sterility in Barley

Abstract

The anther form and development of eight tworowed genie male sterile barley mutants are abnormal. The male sterility in each mutant is conditioned by single non-allelic recessive genes. These mutant genes cause reductions in anther size and lumen diameter. Though in seven mutants, the male meiosis is normal until microspore liberation, the microspores abort in all cases after release from the PMCs. In one mutant, the microspores degenerate at the tetrad stage before release from the PMCs. In four mutants, the tapetal development and disintegration are normal, in four others they are abnormal. Despite these variations, the male sterility in all the eight mutants is complete.Spontaneous male steriles among bisexual flowering plants were first detected by KOL-REUTER(1763) who found anther abortion both within species and species-hybrids. Subsequently, GARTNER (1844), HERBERT (1847) and DARWIN (1890) reported the sporadic occurrence of such atrophied anthers in a few species of Caryophyllaceae, Ericaceae and Liliaceae. Later, many reports appeared about the occurrence of male steriles in hermaphrodites. Male sterility is a firmly-established, geneticallyconditioned and widely-occurring phenomenon known in 162 genera and 43 families of flowering plants (KAUL 1988). It is most frequent in Gramineae. Barley, a diploid inbreeding crop, has over 60 recessive male sterile genes in its genome. Despite their prevalence in barley, anther development events are known in few male sterile mutants even though the main effects of male sterile {ms) genesis on the anther form, development and function KAUL 1990, 1991). The present paper documents this in eight two-rowed barley mutants, male sterility m each mutant is conditioned by a single recessive non-allelic mutant gene. Materials and MethodsTen floral heads from field-grown male sterile and male fertile plants of each of eight barley genotypes, viz., msg7a, msg/b, msgn, msg2o, msg24, msg27, msg32 and msg33 were fixed in FAA (95 % ethyl alcohol 50 ml : glacial acetic acid 5 ml : formaldehyde [40 %] 10 ml : distilled water 35 ml) for 24 h. After thorough washing in double-distilled water, they were preserved in 70 % ethanol at 4 °C. The anthers were dehydrated through an alcohol series, embedded and sectioned at 9 fi. Egg albumin was used for fixing the sections on slides. Stretching was controlled to minimize and standardize the losses of cell ingredients in hot water. The sections were stained with a safranin-fast green counterstain method and mounted in DPX.

Acquirement of a new male sterile germplasm of Chinese jujube

“…In view of its moderate embryo fertility, big fruit-size, and early maturing, 'JMS1' could be used as a valuable female parent in cross breeding. Several abnormal changes of tapetum including hypertrophy, getting vacuolated, and early or delayed disorganization are involved in plant male sterility (Singh and Kaul, 1991;Ilarslan et al, 1999). Hypertrophy and hyperplasia of tapetum were obvious at the tetrad stage of pollen development in 'JMS1'.…”