Collection And Utilization Of Prunus Salicina Germ Plasm Resource In South China

In this paper, the original, economic value, production profile and the significance ofthe study of Prunus salicina are summarized; the variety, the number, the distribution andthe breeding research of it in China and the world are summed up; the main fine varieties inSouth China are introduced. Meanwhile, problems in the collection and utilization of it insouth China were forwarded.This paper explored the relation between pollen viability and storage condition, pollenmorphology, and the correlation between plum fruit, stone and leaf; growth andphysiological changes of plum fruit during maturation were also studied. The results wereas follows:1. The relationship between pollen viability and storage condition Plum pollengermination rate varies greatly among varieties; most of the germination rate is below 40%.This could result in one of the reasons for the low seed setting rate; the best storagecondition of P. salicina pollen is low temperature and dry, it still has some germination rateafter more than three months under this storage condition; under the drying and lowtemperature conditions, light over darkness, but under the room temperature and dryconditions, light over darkness; If pollen need not to be preserved a long time (around onemonth), the storage effect would not be affected under 0-5℃temperature withouthumidity controlling storage condition.2. Pollen morphology Pollen grains of P. salicina varieties are 3-colporate, the typesof N3P4C5. The pollen grains size is in a great difference between the varieties. The pollensize of Sweet Violet, Zaozhuang Red, Beauty, Jade Emperor is medium (25-50um), and therest are big (50-100urn); the pollen of some varieties (including Qingnai,Youlaijiaqingzi,and the 6th plum) is belong to super-prolate spheroid, the rest are prolate spheroid. Thegermination ditch of pole piece of some varieties (including Cellar Door, Xiao Huang, Fu,Kaiyuan, Chuan Ling, BuErBanke) extend deeper, but some varieties (such as Zaozhuang,ShiTianShiShen, the Night Red, Bananas, and Red Plum) of it is shallow. Overall, the P.salicina system in northern China is rather primitive than the one in southern China, such asHubei, Li Hua, Huang Li and others. So it could be speculated that the spread of P. salicinais from the south to the north. Hubei and Fujian province may be the original cultivatingregion of P. salicina. The varieties with different evolutional degrees gradually formed during spreading. The plum varieties in Shandong and Hebei province, particularly inLiaodong Peninsula, are more evolutional.3. Growth and physiological changes during maturation of plum fruit Plum fruitgrowth is double "S" curve, it marks sharp changes of fruit color, hardness, sugar contentand steadily decreasing of fruit acid content in the third period, and the changes are relativeconcentration and with definite orders. Fruit color changed in the previous week of itsripening, while those changes of outdated hardness, sugar and acid content are occurred inthe two weeks before the fruit matured. With the increase of the fruit maturity, fruitcontinued to soften, increase rapidly in soluble sugar content and decrease in titratable acidcontent, and therefore, the hardness, soluble sugar content and titratable acid content offruit can be used as a physiological maturation index. As P. salicina varieties are complex,fruit hardness, sugar content, acid content and fruit colored speed of nearly ripe fruit havegreat difference in varieties. So it is difficult to unify the plum fruit picked time.4. Correlation between plum varieties fruit, stone and leaf There exists positivecorrelation between the vertical, horizontal and side track of fruit and the three tracks of itsstone; positive correlation between fruit flesh thickness and fruit weight, positivecorrelation between fruit weight and leaf nectary. The results reached significance level(1%), respectively. But there is not significant correlation between fruit weight and leafarea.