Research Of Generative Biological Characteristics And Genetic Relationship Of Wild Hawthorn In Xinjiang

In order to study the generative biological characteristics of wild hawthorn resource in Xinjiang, we chose the Altai hawthorn, Crabapple hawthorn and Junggar hawthorn as test materials. We used the paraffin section to observe the developing processof flo-wer bud differentiation, determination of pollen vitalityex by vivo expansion method, cross pollination and observe the surface morphology of pollen grain by scanning elect-ron microscopy; we also did the seed stratification and ISSR marker analyses, the ma-in results were as follows:(1) The flower bud differentiation started in the early July and continued to next A pril. The flower bud differentiation process lasted for about 280 days. The flower bud differentiation period of Wild hawthorn have overlapping phenomenon. Sepals differen-tiation stage, petal differentiation stage, stamen differentiation stage and pistil different-iation stage were coexist in the winter.(2) The most efficient medium for 3 kinds of wild hawthorn pollen germination we-re1% agar + 0.05% boric acid + 15% sucrose, 1% agar + 0.01% boric acid + 15% sucrose and 1% agar + 0.01% boric acid + 20% sucrose.-18℃ was found the most efficient treatments.(3) The single flower pollen amount of Altai hawthorn is significantly higher than o-thers, it is 28 320grains; The natural pollination and self-pollination rate of three kind-s of wild hawthorn is higher than other treatments, they are between 34.83% and 53.10%; the fruit setting rate of self-pollination is ?6%. The cross-pollination rate are be-tween 30.65% and 41.85%. The emasculation by bagging rate are between 4.22% and 11.71%.(4) The shape and color of 3 kinds of wild hawthorn petals are oval and white. Th-ey all have the inferior ovary. The difference of anther color and stigma number of t h-ree kinds of wild hawthorn is obvious; We can get the order by the size of pollen g-rain: Junggar hawthorn > Crabapple hawthorn > Altai hawthorn; The exine ornament a-tion of Junggar hawthorn and Crabapple hawthorn are comparatively dense, the ridge of Junggar hawthorn is more wide than other two hawthorns.(5) Under the variable temperature stratification, the germination rate of the seeds of Altai hawthorn can reach 39.5% when the stratification for 90 d; The germination rat-e of the seed of the crabapple hawthorn can reach 27.1% when the stratification for 150 d. The germination rate of Junggar hawthorn seed was relatively low, the germina-tion rate was only 10.2% after the treatment of 100 mg/L of GA3 and the stratificato-n for 180 d.(6) 221 polymorphism bands were amplified with 12 primers by the ISSR-PCR amp-lification, the percentage of polymorphism loci was 94.4%. The percentage of polymo-rphic loci, observed Number of alleles, effective number of alleles, Nei’s genetic diver-sity and Shannon information index of Junggar hawthorn were higher than other two kinds of wild hawthorn, and the indexes of Crabapple hawthorn were lower than Jung-gar hawthorn and Altai hawthorn. The genetic relationship between Crabapple hawthor-n and Altai hawthorn was closer, but it was farther between Crabapple hawthorn and Junggar hawthorn.