【作者】 黄桂香；

【导师】 薛进军；

【作者基本信息】 广西大学 ， 种植， 2005， 硕士

【摘要】 针对沙田柚存在种子多,果汁较少,自花授粉结实能力弱,或由于良种繁育措施不当,导致品种退化,施肥管理不当、过早采收等,造成果实品质低下,商品率低,经济效益差,从而影响其商品价值和在国际市场上的竞争力的现状,本课题通过杂种选育、营养施肥、修剪、套袋及延迟采收等综合措施进行沙田柚品质改良。 通过对“沙田柚×金堂无核柚”杂交的杂种后代进行培育选择,对杂种群体植株的树体生长量、童期、花期、单果重量、果形、果肉颜色、可溶性固形物含量、种子数、胚性、风味等主要品质性状进行观察测定,分析以上经济性状的遗传趋势,为进一步进行沙田柚育种提供参考;采用营养施肥、修剪、疏果套袋及延迟采收等综合栽培技术措施提高沙田柚果实的内外品质,结果显示: 1、杂种平均单果重731.37g,小于亲中值1165g,可溶性固形物含量为9.18%,比亲本可溶性固形物含量平均值10%低,非加性效应解体,经济性状退化明显;杂种平均种子数为67.47粒,比亲本种子数平均值59.5粒高;有6个单株平均种子数低于20粒,单株平均种子数最少为9粒。而杂种平均可食率为55.72%,比亲本可食率的平均值55.6%高O.12个百分点。 2、杂种果实形状有4种:圆形(亲本型1)占23.3%、长圆形占26.7%、不规则形占43.35%和梨形(亲本型2)占6.6%;除一个杂种单株的成更多还原

【Abstract】 There existed many problems with Shatianyou. Too many seeds, less juice, unsatisfied fruiting with self pollination, poor natural fruit set, varieties degeneration resulting from improper measure of breeding, poor fruit quality and low commodity rate caused by improper fertilizing and early harvesting had affected the commodity value and the competitiveness of Shatianou fruits in the international market. An integrated measure of cross-breeding, properly fertilizing, pruning, fruit bagging and postponing harvest was applied in this study to improve the Germplasm and increase the fruit quality.Referenced theory was obtained for further breeding and variety improving of Shatianyou by breeding and selecting of the hybrid offsprings of Shatianyou×Jintang seedless pumelo, observing and mensurating the growth amount of plants, leaf shape, juvenile period, anthesis, fruit weight, fruit shape, flesh color, total soluble solid content, seed number, embryo characteristics and the flavor of the fruits of hybrid F1 and analyzing the tendency of inheritance of all the economical characteristics mentioned above. A integratedcultivation method of Properly fertilizing, pruning, fruit thinning, fruit bagging and harvest postponing was applied to improve the inner and apparent quality of Shatianyou fruits. The results of the study showed that:1、 The average weight per fruit of hybrid was 731. 37g, being 1165g smaller than mid-parent value. The total soluble solid content for fruits of hybrid was 9.18%, being 10% lower than the average value of parents. And there was an obvious reduction in non-additive effect and degeneration. The average seed number per fruit of hybrid Fl was 67. 47, being 59. 5 more than that of fruits from the parents. There were 6 individual plants showed an average seed number per fruit below 20, and 9 seeds per fruit being the lowest. The amount of edible portion of a hybrid fruit was 55. 72%, showing 0.12% higher compared with 55. 6% of the average value of parents.2、 It was found that there were 4 kinds of fruit shape. Round, elongated round, non-regulate shape and pear shape accounted for 23. 3%, 26. 7%, 43. 35% and 6. 6%, respectively. Except for only one plant of hybrid produced matured fruits of orange in color, other fruits of hybrid had the same color as the parents did, showing yellow in color.3、 There was an obvious reduction in the thickness of the fruit rind. There were two kinds of flesh. One was pink in color of mutation;another was milky-white of parent’ s type. All seeds of hybridprogenies were mono-embryo.4、 The fruits of hybrid matured earlier than those of parents, readyto being harvested at the beginning of October.5、 A prospective hybrid plant was selected, which had thecharacteristics of thin rind, juicy, fewer seeds, pink flesh,moderate acid sugar ratio and easy peeling.6、 Flowering and fruiting were stimulated by means of cutting backafter harvest. It also benefited the control of diseases and pest,increased the apparent quality and the degree of uniform of thefruits.7、 The number of the speckles on the fruit surface from all treatmentsreduced significantly. Treatment of single-layer paper bags showedthe best result, having 3 speckles fewer than control on the surfaceone fruit. There was not any fruit get rotted 60 days after stored.There was no while other qualities did not show No different was foundabout other qualities between the treated fruits and controlledfruits.8、 The yield and the commodity rate were increased by means ofpollination of flower selecting and fruit number controlling. Theweight per fruit, the yield per tree and the commodity rate were thehighest when the fruit number per tree was controlled at the rankof 80 to 100 with a leaf to fruit ratio of 260 to 300:1. 9、 The water content in the flesh, the total soluble solid content, the Vc content and the soluble sugar content were higher than control when self-made nutrition fertilizer was applied. But there was no any difference in the acid content between treatments and control. 10、 Postponing harvest obviou更多还原