| Ricinus communis L. is sorted in Euphorbiaceae and Euphorbia, annual or perennial grass, usually be considered as an important oil plant. Castor content abundant castor oil with excellent quality than other oils, for example:high viscosity, low solidifying point, resistance to both low and elevated temperatures. Researches about castor at home and abroad aims mainly on comprehensive utilization, such as high-yield culture technique, mutation breeding, producing new breed, vegetative propagation, castor oil toxin abstraction and apply etc. Results show that effective way of increasing yield was cross breeding, but number of female flowers has great influence on hybrid rate; Growth and development was regulated by exogenous hormones, especially the six of male and female flowers were affected by exogenous hormones easily. Based on the achievement that previous scholars make, in our study, Xiangbi no.1was took as experiment plant to study exogenous hormones'seed soaking and spraying influences on Castor's growth and development and seed quality, and treating with optimal concentration and processing method is an important way to inducing female flower differentiation, aimed to offer theory support for regulating physiology using exogenous hormones and promoting castor bean production and quality. Our study indicates:1.Different exogenous hormones had different effect on germination rate and germination viability and seedling qualityLow concentration IAA, GA3, KT made little influence on germination rate, germination viability and seedling quality; High concentration(50mg/L) IAA, GA3, KT made influence on germination rate, germination viability significantly, less than75%and20%respectively, but seedling quality was improved and hypocotyls was thick and long, cotyledon was larger; There was low effect on germination rate(77-93%), but high effect on germination viability(0-10%) when seeds were treated by ETH(1mg/L,10mg/L,50mg/L), hypocotyls was short and cotyledon was larger.2.Different exogenous hormones had different effect on vegetative growthCastor's base diameter, height were increased respectively when spraying200mg/L IAA,100mg/L KT; Plant's vegetative growth was inhibited by treatment of seed soaking in10mg/L,50mg/L IAA,1mg/L,50mg/L GA3,1-50mg/L ETH and ETH(200mg/L,300mg/L) spraying.3.Different exogenous hormones had different effect on Castor's inflorescence and female flower differentiationFlowering time was retarded by dipping in50mg/L IAA,1-50mg/L ETH and spraying KT(100mg/L), but flowering time was advanced by spraying ETH(100-200mg/L). Dipping in1mg/L IAA, GA3,1-50mg/L KT and ETH or spaying100mg/L,200mg/L,300mg/L IAA, GA3, KT and ETH had an increase effect on inflorescence length and female inflorescence length, and female inflorescence relative length was significantly increased by dipping in50mg/L GA3, ETH(10-50mg/L) or spaying100mg/L IAA,(200mg/L,300mg/L) GA3, that was said female flower differentiation was promoted obviously. But female inflorescence relative length was shorted by dipping in50mg/L IAA, female flower differentiation was inhibited.4.Different exogenous hormones had different effect on Castor's ear and fruit qualitySeed soaking in exogenous hormones:In contract to control, ear was elongated significantly,1000-grain weight was reduced, oil content was decreased by1mg/L IAA,1-50mg/L GA3,1mg/L and50mg/L KT; There was no obvious effect on1000-grain weight, but oil content was increased by10mg/L KT,1mg/L and10mg/L ETH. Spaying exogenous hormones:There was little effect on ear and1000-grain weight, but oil content was increased by5.9%,4.8%,5%when treated by200-300mg/L IAA,100mg/L GA3; Oil content was decreased by8.8%,5.4%and3.4%particularly by spaying300mg/L KT,200-300mg/L ETH.5.Different exogenous hormones had different effect on castor oil plant endogenous hormones contentDifferent exogenous hormones and methods had different effect on castor oil plant endogenous hormones(IAA,ABA,GA3,ZR) content before, during and after florescence. For example, endogenous hormones IAA and ABA before florescence, IAA during florescence, IAA, ABA, and ZR after florescence were decreased significantly by treatment of1mg/L IAA seed soaking. Endogenous hormones IAA before, during and after florescence, GA3before florescence, ZR after florescence were decreased by ETH(100-300mg/L) spraying, but GA3during florescence were increased.6.Different exogenous hormones had different effect on castor flowering and fruitingThere was some correlation between four kinds of exogenous hormones and castors' flowering and fruiting by different exogenous hormones. For example, there was a very significant positive correlation(r>0.7) between endogenous hormones (IAA+GA3)/ZR after florescence and female inflorescence length when seed soaking in exogenous hormones; Endogenous hormones (IAA+GA3+ZR)/ABA before florescence and1000-grain weight appeared very significant positive correlation(r=0.841); There was no correlation between four kinds of endogenous hormone and oil content.In a word, germination rate and germination viability(20d after sowed) was decreased by soaking in1-50mg/L IAA, GA3, KT and ETH compared to control group. Vegetative period was prolonged by soaking in exogenous hormones, but was ahead by spraying exogenous hormones. Growth potential was increased by soaking in1mg/L IAA,10mg/L GA3,1-50mg/L KT; Vegetative growth was inhibited by ETH, but was promoted by spraying other kinds of exogenous hormones. Flowering time was advanced by spraying100mg/L ETH, Female inflorescence and the ratio of female inflorescence:total inflorescence was increased significantly by soaking in10-50mg/L ETH and spraying200-300mg/L GA3. Oil content was increased by5.6%,5.9%,5%,1.5%respectively by soaking in l0mg/L ETH and spraying200mg/L IAA,100mg/L and300mg/L GA3. Endogenous hormones ZR during florescence was increased significantly by soaking in50mg/L ETH, spraying IAA, GA3, KT and ETH has a great effect on endogenous hormones IAA and ZR. There was no correlation between four kinds of endogenous hormone and oil content. |
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