Establishment And Optimization Of Anther Culture System For High Resistance Starch In Rice

Functional rice is rich in the functional components, such as resistant starch, amino acid and flavonoids and so on. Functional rice is the new rice varieties, which can improve the physiological functioning of the human body. Currently the rice can be cultivated by means of biotechnological breeding and genetic engineering techniques which may increase the functional ingredient content. The functional rice could have been linked with a reduced prevalence of hypertension, hyperglycemia, obesity and other chronic diseases that caused by the irrational diet. At present, food therapy could provide an effective way to prevent the chronic diseases and be benefit to solve the sub-health problem.Zaxima is a kind of indica rice variety in Yunnan Province, which is rich in resistant starch, which the content of RS is up to8%. Nanjing46is ajaponica variety that is delicious for texture and flavour, which be cultivated by Institute of Food Crops, Jiangsu Academy of Agricultural Sciences. The anthers of F1from crosses of indica and japonica varieties "zaxima"/"nanjing46" is used for explants to establish an efficient regeneration system of hybrid F1of indica and japonica varieties. The main results are as follows:1. The anther regeneration system of the hybrid F1is established. It is found that spikes are treated under low temperature for2-5days, cultured on N6or M8basic medium adding1-2mg/L2,4-D,1-3mg/L NAA,0-0.3mg/L KT and sucrose60g/L. The callus can be induced from the anther, and the rate of callus induction is up to4.34%-32.14%. The callus is cultured on the MS differentiation medium adding KT2mg/L+ABA3mg/L, which can regenerate green plant, and the rate of plant regeneration is up to4.55%. The green seedlings are cultured to form complete plants on the MS root medium, without the addition of exogenous hormones.2. With the long-term natural evolutionary selection conditions, Oryza sativa L are divided into the indica rice and the japonica rice, which have a certain degree of reproductive isolation. According to35pairs InDel molecular markers, that can identify the indica-japonica types. Zaxima, Nanjing46and the regeneration of anther culture of F1hybrids are identified, it is found that Zaxima is the typical indica, Nanjing46is the typical japonica rice, the hybrid F1and the regeneration plants are intermediate types between indica and japonica or indica-japonica. 3. Low temperature pretreatment is a critical step to anther tissue culture, but the researches on the relationship between the anther morphology and low temperature treatment are very scarce, and yet not well-rounded. Distribution of polysaccharides. lipids, and proteins in the developing anthers of rice is examined with different cold treatments by the cytochemical methods. It is observed that the content of carbohydrates can increase significantly after2d cold treatment in the pollen wall, the cold treatments can promote the degradation of proteins into amino acids, but lipids metabolism is little affected.4. The content of resistant starch is measured of37regeneration plants by the resistant starch assay kit. It is found that the resistant starch content of regenerated plants is between the content range of their parents, which is the normal distribution and female bias. The content of resistant starch (1%-3%) is86.5%, the resistant starch in3%-8%is accounting for13.5%.