Morphological Observation And Quality Research In Banana Radiation Lines

Banana is an important tropical and subtropical fruit tree, which is the fourth fruit after apple, pear, and citrus in the world. At present, triploid banana varieties is mainly cultivated. Because of its close relative and the narrow genetic basic can lead to degradation of varieties seriously. At the same time, these varieties delay the progress of banana breeding innovation because of its parthenocarpy and highly sterility. It is difficult to breed new variety and to improve banana fruit quality by traditional methods of cross breeding. So radiation mutagenesis is an ideal approach to create new varieties in banana. In my study, banana callus and buds from immature male flowers as explant material were induced by60Co-y radiation mutagenesis and then picked out368explants from5000mutagenic materials which grew well. Six lines filtered through the comparison with the control and transplanted to banana germplasm nursery of Tropical Biological Technology Research Institute, Chinese Academy of Tropical Agriculture. Then the agronomic characters were observed and the fruit quality was detected and valued. The main results are as follows:1. Compared with the control, false stems of optimizing1-5lines were height and thick. Blades of optimizing1-3lines were long and wide. Moreover, growth period of optimizing1-3lines was advanced11days than that the control. Leaf length and width of optimizing4and5lines were less than the control, but leaf number was more than the control, growth period of optimizing4and5lines was delayed8days than that the control. Length and quality of the fruit bunch of six optimum lines were significantly higher than the control (p<0.05). Fruit number per panicle were similar, but each comb and fruit quality index was higher than that the control.2. Compared with the control, fruit external quality of six optimum lines were as follows:fruit weights of optimizing1-6lines were significantly higher than the control (p<0.05). Fruit finger length of the optimizing3was21.8cm, which was the highest among six lines. The lowest was optimizing2, which was16.4cm. In fruit finger roughness, optimizing3was the highest and the control was lowest. Finger roughness of optimizing1-6was significantly higher than the control. Fruit peduncle of optimizing5was the highest and the others were unaffected. Fruit skin brightness of optimizing2and3was significantly higher than the control. Rind brightness of the other lines were no significant difference than that the control.3. Compared with the control, fruit internal qualities of six optimum lines were as follows:the edible rate of optimizing3and4were the highest, which were no significant difference with the control (p>0.05). Besides optimizing6, total starch, amylose/amylopectin, and resistant starch content of the other five lines were significantly higher than the control (p<0.05). Besides optimizing2and6, amylase/amyl pectin of the other four lines were significantly lower than that the control. In the sugar composition and content, optimizing1,3,5contained fructose, sucrose and glucose, D-xylose and maltose, and optimizing4and6contained fructose, sucrose and glucose, and maltose. Total sugar content of the control was the highest, optimizing1-6were significantly lower than control (p<0.05). Six optimum lines of banana fruit were given priority to with quinic acid, oxalic acid, and malic acid, moreover, containing different amount of tartaric acid, a-ketoglutaric acid, citric acid, fumaric acid and succinic acid. Total organic acid amount of optimizing5was the highest and optimizing6was lowest. Total organic acid of optimizing1,4,5were significantly higher than control, and optimizing2,3,6, were significantly lower than that control (p<0.05).4. Compared with the control, important functional ingredients of fruits in six optimum lines were as follows:Vitamin C content of optimizing4was13.12100mg/g and it was the highest among six lines, which was significantly higher than that the control (p<10.02mg/g0.05), but the vitamin C content of optimizing2and5was relatively small. The highest flavonoids content of optimizing3was2.17mg/g. flavonoids content of optimizing2was the lowest and it contained only0.33mg/g. Among them, flavonoids content of optimizing1,3,4were significantly higher than that the control and optimizing2and6was significantly lower than that the control.5.12main quality indexes determined in banana fruit was extracted the four principal components (characteristic value>1) through component analysis. We found that the cumulative contribution rate of four principal components was approximately96.484%. Total information amount of quality index was summarized. The first principal component mainly covered the fruit weight, edible rate, total flavonoids, total starch, and amylose/amylopectin, they were the most important principal components. The second principal component mainly included skin brightness, vitamin C, and organic acid. The third principal component mainly covered the fruit length, fruit coarse, and resistant starch. The fourth principal component was mainly soluble sugar.6. Comprehensive evaluation of fruit quality in six lines and the control was performed according to four principal components factor. The order of fruit quality was as follow:optimizing3line> optimizing4line> optimizing1line> optimizing -5line> control> optimizing2line> optimizing6line.