| Nanbu pomelo（Citrus grandis）is a local excellent citrus fruit variety in Nabu county of Sichuanprovince, with a good market reputation for its crisp pulp (juice vesicles), good taste, moderate ratio ofsweetness and sourness as well as rich nutrition. However, the rate of split fruit of Nanbu pomelo is veryhigh during pre-harvest, usually at30%, even70%in some years. So, it is urgently needed to decreasethe rate of split fruit. In this study, Nanbu pomelo was taken as the experimental material and the effectsof pollination and plant growth regulators on fruit set, fruit split and fruit quality were studied throughpollination with the pollens of Shatian pomelo, Jiangyongxiang pomelo, Guanxi pomelo and Bendisuanpomelo and different concentrations and combinations of the growth regulators of GA3and6-BA. Theresults were as follows:1.The fruit set rate of Nanbu pomelo was improved by the pollinating of the four pomelo varieties,among which the pollination of Guanxi pomelo and Jiangyongxiang pomelo were best. The differencewas significant and their fruit set rates were increased by17.00%and14.34%, respectively, comparedwith the control group. However, the effects of growth regulators on fruit set were not significant.2.The fruit split rates of the four pollination treatments were below10%and were significantlylower than the control group. Among which Guanxi pomelo pollination treatment had the lowest fruitsplit rate of1.70%, followed by Jiangyongxiang pomelo pollination treatment(2.73%) and Bendisuanpomelo pollination treatment(3.57%). Shatian pomelo pollination had the highest fruit split rate (7.30%).Different growth regulator treatments also reduced fruit split rate. GA(20mg/kg), GA(40mg/kg),BA(200mg/kg),GA+BA(10mg/kg+100mg/kg),GA+BA(20mg/kg+200mg/kg)andGA+BA(40mg/kg+400mg/kg) significantly decreased fruit split, and GA+BA (40mg/kg+400mg/kg) had the best effectwith a lowest split rate of27.34%of the control group, the next was GA+BA (10mg/kg+100mg/kg) andGA+BA(20mg/kg+200mg/kg), with split rates of53.65%and54.32%of the control group,Respectively.3.The fruit yield of Nanbu pomelo was significantly improved by the pollinating of the fourpomelo varieties, and the trees pollinated by Guanxi pomelo got the highest yield((51.04kg). However,no significant difference was found among the four pomelo variety pollinations. The growth regulatortreatments also improved the fruit yield of Nanbu pomelo, and GA+BA(40mg/kg+400mg/kg) treatedtrees got the highest yield (13.99kg)，but no significant difference was existed among the growthregulator treatments and control.4.All the four pollination treatments increased the total fruit seeds (well-developed seeds+abortedseeds) in Nanbu pomelo fruits. However, compared with the control, Shatian pomelo and Guanxipomelo pollination treatments had no significant effects on increasing fruit seeds. Guanxi pomelopollination treatment reduced Nanbu pomelo fruit shape index, making the fruit in a shape of depressedglobose. Jiangyongxiang pomelo pollination treatment reduced the thickness of the Nanbu pomelo peel.The pollination treatments of Shatian pomelo, Guanxi pomelo and Bendisuan pomelo made the central columns of the Nanbu pomelo fruits become remarkably smaller. Guanxi pomelo pollination treatmentimproved Nanbu pomelo fruit surface brightness and more red in color. Bendisuan pomelo pollinationtreatment significantly incereased the yellowness and smoothness of Nanbu pomelo fruits while theother3pollination treatments had no significant effects. All pomelo pollination treatments significantlydecreased Nanbu pomelo fruit Vc contents. Except for significantly increase of fruit titrable acidity ofNanbu pomelo fruits by Jiangyongxiang pomelo pollination, all pollination treatments had nosignificant effects on Nanbu pomelo fruit weight, edible rate, total soluble solid contents(TSS), titrableacidity(TA) and ratio of TSS/TA.Total fruit seeds of Nanbu pomelo were not significant between the nine growth regulatortreatments and the control. All growth regulator treatments increased fruit peel thickness, andGA+BA(40mg/kg+400mg/kg) resulted in the thickest fruit peel and also significantly thicker than thecontrol fruit peel. The treatment of BA(400mg/kg) had remarkably lower edible rate than the controlwhile other regulator treatments had no significant effects. There was no difference in fruit brightness ineach treatments and control. the fruit yellowness of treatments of GA(20mg/kg), BA(400mg/kg) andGA+BA (20mg/kg+200mg/kg) were remarkably higher than the control. Regulator treatments had nosignificant effects on fruit soluble solid contents, titrable acidity, Vc content and ratio of TSS/TA.As stated above, Nanbu pomelo pollinated by Guanxi pomelo variety had the best fruit set, fruityield, the lowest fruit split rate and the smallest adverse influence on fruit quality. Therefore, it issuggested that Guanxi pomelo should be as the pollinizer of Nanbu pomelo in production. |
PDF Full Text Request