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China was the first country to use cytoplasmic male sterility to develop hybrid rice for commercial use in 1973. In 1986 more than 8 million hectares of hybrid rice were planted in China, which is one fourth of the total rice area and produces one third of the total rice in the country. Hybrids usually out yield the leading commercial varieties by -20-30%, giving an average yield advantage of 1 to 1. 5 t/ha, because of their better morphological traits, higher physiological efficiency, better resistance to major diseases and insects, and wide adaptability to various agro-ecological stresses. IMPROVEMENT OF HYBRID RICE A. Mutation techniques Almost all of the cultivated F1 rice hybrids in China are developed from cytoplasmic male sterile and restorer lines. According to surveys made in recent years, more than 30 sources of cytoplasmic male sterility in rice can be identified, among which only six are being commercially used (Table 1). Wild rice with aborted pollen (WA) cytosterility system is the most popular one in use to develop male sterile lines (MS line) in China. The main technique available for developing stable MS lines is sUbstitution backcrossing of the genome of one species into alien cytoplasm of another. Sufficient backcrosses are required to eliminate all nuclear genes derived from the cytoplasm donor species. A number of studies have shown that using interspecies crosses, such as the cross of wild rice (Q. perennis, Q. sativa, f.
Inhaltsverzeichnis
Project Reports and Invited Papers.- Quantifying gametoclonal variation in wheat doubled haploids.- Breeding on a cellular level, and research on hybrid F1 development.- Use of high pairing wheat mutants for the transfer of useful traits from alien species into cultivated wheats.- Male sterile facilitated recurrent selection.- Wide hybridization for cereal improvement.- The effect of dwarfing genes on the expression of heterosis for grain yield in F1 hybrid wheat.- A summary on current status of hybrid rice improvement by using induced mutations and in-vitro techniques.- Production of haploids in cereals.- Somaclonal selection of physiological mutants through plant cell culture.- Exploitation and analysis of heterosis in wheat with induced mutations.- Barley mutants - diversity, genetics and plant breeding value.- Barley mutant heterosis.- Rice improvement (involving altered flower structure more suitable to cross-pollination) using in-vitro biotechniques in combination with mutagenesis.- Use of doubled haploid lines in recurrent and natural selection in barley.- Commercialization of the bulbosum method in barley (Hordeum vulgare L.).- Induced mutagenesis to facilitate heterosis and hybrid seed production in barley.- Some prospects of hybrid triticale breeding.- Induction of salt tolerance in high-yielding rice varieties through mutagenesis and anther culture.- Short Communications.- Crossability of spring barley mutants with H. bulbosum.- The commercial application of cereal haploidy..
Bericht
`... the book contains some papers which will be of interest, mainly to plant breeders and geneticists.'
Plant Growth Regulation 9, 1990
