11 Jan Male Sterility Systems in Wheat for Commercial Hybrid Seed Production
गेंहू के व्यवसायिक संकर बीज उत्पादन के लिए गेहूं में मेल स्टेरिलिटी सिस्टम Exploitation of hybrid vigour at commercial level through development of hybrid wheat is considered as one of the promising approach for increasing wheat productivity. Work on hybrid wheat started world over in 1962 and utilization of heterosis through hybrid breeding has given very high dividends in many field crops including horticulture. The discovery of an effective cytoplasmic male sterility and pollen fertility restoration systems in wheat opened up new avenues for commercial hybrid seed production. Kihara (1951) pointed out the possibility of using male sterility by transferring the nucleus of common wheat into the cytoplasm of Aegilops caudata. Among the cytoplasms which in an interaction with Triticum nucleus bring about sterility, T. timopheevii seems to be the most suitable one for commercial production of hybrid seed. Wheat is monoecious and therefore, a line designated as female must not be allowed to produce pollen capable of fertilization while acting as a parent. As wheat flowers are hermaphrodite, the labour requirement for mechanical emasculation is very high. Methods for procuring male sterility in plants may be genetically controlled including cytoplasmic male sterility, nuclear male sterility and self-incompatibility or through chemical hybridization agents or hand emasculation. Three methods for obtaining male sterility have been proposed...