Studies On Effects Of Selfing On Main Characters Of Brassica Napus L.

Brassica napus L. is an often cross-pollinated plant, and is not generally considered selfing recession, but it was little reported about effects of selfing on main traits of Brassica napus L. In this experiment four Brassica napus L.lines as the test materials, the changes of major economic traits, growth period, protective enzyme activity were studied after four years selfing, and the impact on Brassica napus L. by selfing were discussed. Key findings are as follows:1. Selfing had significant impacts on the main economic characters of Brassica napus L. Plant height, branch height, effective branch, No. of pods in the main inflorescence, No. of pods of whole-plant and yield per plant were reduced as self-generations increased. The correlation coefficient between the major economic traits and selfing is from -0.979 to 0.289, and selfing with plant height, branch height, the number of pods of whole-plant, yield and other traits was a significant negative correlation; while the impact on seeds per pods and 1000-seed-weight was smaller. In addition to 03wu240-1 participant strains , the growth period of Brassica napus L which was selfing four years was a week ahead of that of open cross pollination plants, the remaining three lines did not have any changes.2. Compared to open pollination, oil content and protein content of self-generations significantly decreased(P <0.05), the correlation coefficient was between -0.980 and -0.724, with a remarkable negative correlation; but the difference of changes of erucic acid and glucosinolate content between self-pollination generations and the opening-up was not significant.3. The SOD,CAT and APX had peak activity in the early anthesis, and the self-generation was significantly lower than open pollinated; POD activity in squaring period and anthesis had two peaks, and which both of the open pollinated were higher than those of self-generations respectively; the POD isozyme of four strains at five-leaf stage were smaller, but the activity of the POD isoenzyme of open pollination were stronger than those of self-generations;While the EST isozyme of the open pollinated were stronger than self-generations, with 11 bands.4. The seed-setting rate decreased as the self-generation increased, and which is significantly lower than OP (open pollinated groups).The correlation coefficient was between the -0.992 and -0.791.The 03wu240-1 turned into self imcompatible in the fourth self-generation(SC index <1). Strictly selfing made the self compatible index and seed-setting rate of Brassica napus L down.5. The impact on Brassica napus L was studied after continuous strict selfing with29 pairs SSR primer. Six pairs polymorphism SSR primer were obtained, with a total of 35 alleles variations, each primer detected five to eight allele, an average of 5.83. UPGMA clustering analysis showed that 20 tested materials can be divided into four broad categories, in each strains the open cross pollination with their responding self-generations clustered together.In a word, selfing had a significant impact on Brassica napus L traits, which led to the lower height and yield, the decrease of grain oil and protein content, the decline of seed-setting rate, the reduction of enzyme activity at anthesis stage.