Sterilty Induced By A Novel Chemical Hybridization Agent(Cha) EN And Its Utilization In B Napus

There are two ways in utilization of heterosis in rapeseed .One is three lines ,another is two lines.The CMS is a efficient and extentive approch for three lines .The CHA is also a major approch for heterosis utilization.A novel CHA EN, was selected in order to investigate effect of CHA on sterilty in rapeseed in this study. The dosage of EN, spraying period and spraying pattern were studied , next effects of EN on flower , vigor of pollen grain, agronomical characters were investigated ,at last inflence of EN on male sterile line was surveyed for the sake of expecting to provide experimental data for rapeseed breeding. Total nine accessions of Brassica napus, most of them are inbrid line,S3116,S30,S 1188,S 1195,S 1102 and S1112 , others is male sterile lines, 212A, 203A and 208A ,were used in this study. The ace to-carmine dyeing check method was use to investigate vigor of pollen grain , ability of EN induced sterility is adjust according to morphology of flower , vigor of pollen and setting rate in the feild.The results Showed that as follows:1. The induced sterility effect of EN on rapeseed is various with spraying date , dosage and spraying pattern of EN . Good effect could be obtain by spraying EN with 0.1-1.0 μg/ml concentration during mono-nucleus microspote., the optimal concentration of EN is 0.5-0.8 μg/ml.2. EN concentration 0.5-0.8 μg/ml could acquire better sterilty . The rate of sterile plants is 100 percent, rate of full sterile plants above 95 percent. A single plant sprayed with EN is normal agronomiacl traits , no seed by pollinate in bag, normal setting at open pollination .3. In flower treated with EN , anther is neddle-like , fade , no pollen grain and wrinkle or empty ,distorted pollen grain. Filament is shorten .The morphylogy of flower is like that of nuclear male sterility.4. A good act that amout of normal pollen is decreased are obtained when EN sprays on unstable cytoplasmic male sterile lines.About 98 percent of CMS lines can be decreased the amount of normal pollen by spraying EN during 2-5 d ofmono-nucleus microspote stage.This method can make purity of hybrid up 8 percent.5. EN can be implied for inbred lines of rapeseed .A CHA hybrid can be developed through spraying EN on inbrid lines which can be used as maternal parent .A CHA variety breeding need not to develop special male sterile lines and restorers, therefore, its parents can be selected randomly and widely . It is easy and rapid to develop a variety with high yield, good quality, resistant to diseases .