| Common wheat (Triticitm aestivwn L.) is grown across a wide range of environments around the world. Wheat is the number one food grain consumed directly by humans, including rice, maize, and potatoes. China is the largest wheat producer in the world. Wheat is the second leading cereal crop in China, with annual wheat area and production totaling 28 million ha. and 120 million tons. Chinese population is predicted to reach 1.6 billion people during the next 30 to 40 years. It will be need to double the supply of food during this times, just to keep pace with population growth. Wheat is a leading national food source. Wheat will no doubt become more important, which underscores the need to rapidly and continuously increase production. Greater wheat production can be achieved in two ways only: (i) by expanding the area sown, and (ii) by improving the yield per unit of area sown. It will be small room to expand the area sown. Because the fanning land will be used to grow wheat will decrease year after year. The area of nonagricultural uses will increase every year. Increased use of productive agriculture lands for growing wheat is not likely. Especially starting from 1998, Chinese government put more attention to agriculture ecosystem More trees have been planted on side of hill where had been sown wheat before. So the area sown of wheat decreased every year. In order to provide enough food to people and to meet the increasing grain demands in our country, increased wheat production must get from higher yield. Greater yield per unit of area sown can be achieved in many ways. Utilizing heterosis in crop is an important way to increase yield. The successful utilization of heterosis in rice, corn, oil rapeseed and other crops give hybrid wheat breeders a bright future. Now there are three methods used for producing hybrid wheat seed, including cytoplasm male sterility (abbreviated CMS), chemical hybridization agents (abbreviated CHA) and nucleus male sterility (abbreviated NMS). Comparing with those three ways, CHA system is an important method to produce hybrid wheat seed. The CHA system can simplify and increase the efficiency of the hybrid breeding programs, and dramatically increase the range of germplasm that can be utilized in development of hybrids. The male and female parents can be chosen freely from wheat conventional varieties. The development of a successful CHA system must have a reliable hybridization technology. In an other words, an effective CHA is bottleneck in hybrid wheat research program. GENESIS has been used successfully in many geographical areas in Europe and U.S.A. Several hybrid wheat varieties have been produced commercially using GENESIS Hybridization agent, which was developed in the USA by Monsanto Company. In 1996, the former Northwest Agricultural University (Northwest Sci-Tech University of Agriculture and Forestry) cooperated with Monsanto Company and introduced GENESIS (MON21200) into China for efficacy test. After 3 years efficacy test and genotype test, more than 500 genotypes were screened. The results indicated that GENESIS could induce completely male sterility, no strong interaction and side effect onfemale fertility was found among genotype and GENESIS under commercial rate. All results were proofed that GENESIS was a promising CHA for wheat in commercial hybrid wheat production. In 2000, one hybrid named XiZa NO.1 was released by Northwest Sci-Tech University of Agriculture and Forestry. In order to develop and to utilize GENESIS effectively, and to understand of the mechanisms involved in male sterility, and to get more knowledge about male sterility inducing by GENESIS, and to screen new CHA bttter, it is essential to study the mechanisms of pollen abortion in male sterility induced by GENESIS. In this paper, by using the methods of semi-thin and thin section, ultrastructure in the inline of K-Yun A (male sterility line with Ae. Kotschyi cytoplasm), CHA-Yun B (male sterility induced by GENESIS) and 77(2) (male fertility as a check) were comparatively studied. Effects of...
|
PDF Full Text Request