| In this thesis,varieties with red peel,red and white pulp were used to study the pollination characteristics of pitaya,including the flowering biological characteristics of pitaya,the factors affecting pollen germination and pollen tube growth,pollen characteristics and storage conditions of different varieties,and the selfing and outcrossing characteristics of different varieties;by observing the germination and elongation of pollen in style to identify the self-incompatibility mode of pitaya,and clone the S gene associated with self-incompatibility in pitaya.This study provides reference for increasing the efficiency of pollination in production and accelerating the process of artificial cross breeding,it is also benefical to the further research on the self-incompatibility mechanism in pitaya.The main results are as follows:(1)Pitaya florescence 5-7 month,11-14 group spent a year,flowers open in the evening,the single flower opening time is 12-14 h.From pitaya to observe the red flower bud stage of fruit ripening lasted 48 days.The self-compatible and self-incompatible cultivar varieties in flower structure existence difference,self-incompatibility compatible varieties less stigma lobes,stigma prominent,avoid self pollination and self-compatible cultivars;stigma lobes are more conducive to the anther stigma surrounded by self pollination.(2)Pitaya pollen is more round 80 μm,are tricolporate type.The difference in different varieties of pitaya pollen size,Dahong and Hongshuiing pollen,white flesh,Yuehong,Lianhuahong and Shihuoquan pollen size center.The single anther pollen quantity difference between different varieties,the largest number of Yuehong pollen is red varieties followed by Shihuoquan varieties,two pollen pollen number were significantly more than the minimum number of Baishuijing varieties.The Baishuijing species in pollen size,anther pollen number were tested varieties in the lowest.(3)With pitaya group effect of germination of pollen,the pollen density appropriate help to improve the rate of pollen germination.In vitro,the pollen germination and pollen tube growth tends to be stable after 10 h.The pollen germination temperature range,optimal germination temperature of 25 ℃-28 ℃.In vitro pollengermination rate and self-compatibility on the strength of low germination rate with self-compatibility strong pollen.(4)The effects of sucrose,boric acid and pH value on pollen germination and tube growth were extremely remarkable,and there was a significant interaction between them.The influence on in vitro pollen germination rate was boric acid × sucrose >sucrose> sucrose × pH> boric acid > boric acid × sucrose × pH >pH> boric acid × pH,the influence on the pollen tube length was sucrose >pH> boric acid × sucrose > boric acid > boric acid × pH> sucrose × pH> boric acid × sucrose × pH.Here the optimum culture medium for the pollen germination was observed at 500 mg/L boric acid,25%sucrose and pH 6.5,and the optimal culture condition for pollen tube elongation was300 mg/L boric acid,20% sucrose and pH 7.5.(5)Between different pitaya pollen vitality is large,the highest red to 80.7%varieties,Shihuoquan pollen vigor stone lowest only 25.9.Experiments to compare the changes of two kinds of different preservation methods on pollen vitality of pitaya.The dry preserved 12 h pollen after inactivation,not drying at room temperature.The change in 4 ℃ pollen preservation the refrigerator pollen live performance is decreased first and then rebound phenomenon,pollen viability changes do not follow the general rules with the increasingly long time decreased.Pitaya may change pollen viability and illumination,humidity,temperature and other factors.(6)Hongshuijing,Lianhuahong,Yuehong 3 self incompatible cultivars and self-compatible cultivars were white cross pollination,the result shows that the three setting rate than the other "self-incompatible pollen,are linked to pitaya cross pollinated fruit set and pollen adorable flower powder adorable force,the stronger force setting rate more high.In addition,the Shihuoquan pollen vitality of the lowest,and the 5 cross pollination combination of Hongshuijing,"Hongshuijing×Shihuoquan" fruit rate is lowest,further explained that there is a direct relationship between pitaya cross pollinated fruit set and pollen viability.(7)Pitaya selfed pollen can germinate on the stigma and can stretch in the style,gametophytic self-incompatibility.Corresponding with the development of the pollentube is through pollination experiments showed red crystal and Yuehong 2 varieties of self pollinated fruit set barely two,cross pollination and fruit setting rate is much higher than the self pollinated fruit setting rate of self pollination.The pollen tube was relatively slow,would be an important cause of pitaya self-incompatibility.(8)In the pitaya style,pollen cloned S-RNase gene,F-box gene.The 2 genes obtained by bioinformatic analysis,the prediction results show that the protein molecular theory of molar mass of S-RNase gene encoding 25.57 kD,isoelectric point was 9.31 pI,the half-life of more than 20 h,is a stable protein,protein molecular theory of the molar mass of the the amino acid sequence contains 2 conserved functional domains of.F-box gene encoding for 40.70 kD,isoelectric point of pI was 5.19,the half-life of F-box protein is more than 20 h,which belongs to the unstable protein,its amino acid sequence is a conserved domain... |
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