Study On Flowering And Pollinating Characteristics And Effect Of Flower Thinning By Lime-sulfur Of Precocious Walnut

In order to improve the yield and quality of precocious walnut, full fruit period ofLvling, Liaoning1, Luguo1Shangsong6, Zhonglin1, Lvzao which were planted in HebeiLvling Fruit Co. Ltd. were used as materials to study the flowering phenophase, pollenmorphology, pollen storage characteristics, pollination and fruiting characteristics,effect offlower thinning by lime-sulphur with the methods of morphological observation,microscope observation, TTC staining, benzidine and hydrogen peroxide, spraying thelime-sulfur.The results were as follows:1、The male flowering periods of male first walnut cultivars that of Lvling, Liaoning1,Luguo1were4~5days, pollen dispersal periods were from April14th~17th, female flowerflorescence periods were14~15days, female flower blooming period was about April25th.The male flowering periods of female first walnut cultivars that of Shangsong6,Zhonglin1, Lvzao were11~12days, pollen dispersal periods were from April25th~28th,female flower florescence periods were15~16days, female flowers blooming period wasabout April15th,Therefore male first walnut cultivars and female first walnut cultivarscould be used as mutual pollination cultivars that they may cross-fertilize.2、When Luguo1was as female parent, the fruit setting rates which pollinated byShangsong6, Zhonglin1, Lvzao were33.33%,33.61%,29.44%; kernel rates were51.52%,53.61%,48.40%; nut weights were11.73g,10.90g,11.44g; soluble protein contents were2.31%,1.88%,2.67%. When Lvling was as female parent, the fruit setting rates whichpollinated by Shangsong6,Zhonglin1, Lvzao were35.83%,26.11%,27.77%; kernel rateswere62.03%,61.46%,59.56%; fruit weights were11.44g,10.10g,10.02g; solubleprotein contents were2.24%,1.67%,1.84%. When Liaoning1was as female parent, thefruit setting rates which pollinated by Shangsong6,Zhonglin1, Lvzao were27.66%,20.99%,22.84%; kernel rates were54.41%,59.94%,59.50%; fruit weights were11.36g,10.21g,11.25g; soluble protein contents were3.02%,1.76%,1.69%.3、The pollen grain shapes of the6precocious walnut cultivars were suborbicular tocircular, circular pollen grains accounted for about20.41%; suborbicular pollen grainsaccounted for about79.59%. Lvzao had the highest circular pollen grain proportion whichwas25.83%; Lvling had the lowest circular pollen grain proportion which was15.83%.Theaverage diameter of the pollen grain was39.60μm, the average diameter of Liaoning1 pollen grain was the largest, which was43.32μm, and that the smallest was Zhonglin1,which was36.67μm, the difference was6.65μm, In the same cultivar, the difference ofthe maximum and the minimum diameter was11.87~22.50μm.4、 With the pollen viability maintained at20%as the standard, under roomtemperature, pollen storage days of Lvzao, Zhonglin1, Shangsong6, Luguo1, Liaoning1,Lvling were8days,7days,9days,11days,10days,10days; under4℃storage condition,pollen storage days of Lvzao, Zhonglin1, Shangsong6, Luguo1,Liaoning1, Lvling were27days,30days,35days,50days,50days,45days; under-20℃storage condition, pollenstorage time which kept its viability was the longest, which was above180days.5、The fruit setting rates of ’Llvling’ walnut which were pollinated in stigma crackingperiod, eight-formed period, anti-roll period were22.39%,30%,21.39%.6、After sprayed lime-sulfur on ‘Lvling’ male inflorescence, the pollen viabilitiesincreased first and then decreased as the sprayed days increased, the pollen vitalities wereon a downward trend with lime sulfur concentration increased.The effects of sprayeddifferent concentrations of lime sulfur during the male inflorescence elongation stage hadno significant effect on pollen viability.After sprayed lime-sulfur for3d during the floretseparate stage, pollen viability was the highest,and those were79.00%,75.67%,71.67%when the lime-sulfur concentrations were0.5°Be,1.0°Be,1.5°Be, that control was88.33%;after sprayed lime-sulfur for4d, pollen viability was the lowest, and those were42.33%,34.33%,34%when the lime-sulfur concentrations were0.5°Be,1.0°Be,1.5°Be, thatcontrol was47.67%; after sprayed lime-sulfur for2d during the male early flowering stage,pollen viability was the highest, and those were79.33%,74.67%,73%when thelime-sulfur concentrations were0.5°Be,1.0°Be,1.5°Be, that control was88.33%; aftersprayed lime-sulfur for3d, pollen viability was the lowest, and those were42.00%,34.00%,31.00%, that control was48.67%.7、After sprayed with0.5°Be,1.0°Be,1.5°Be lime-sulfur during the stigma crackingperiod, the fruit setting rates were respectively50.24%,39.55%,35.92%, that control was54.32%; the average three diameters were33.9mm,34.7mm,34.7mm, that control was34.4mm; nut weights were10.36g,10.65g,10.86g, that control was10.28g; kernel rateswere62.75%,63.61%,64.20%, that control was62.83%; fat contents were66.60%,66.54%,66.49%, that control was66.42%. After sprayed with0.5°Be,1.0°Be,1.5°Belime-sulfur during the flowering period, the fruit setting rates were54.67%,38.50%,35.63%respectively, that control was56.40%; the average three diameters were34.0mm,35.3mm,35.7mm, that control was34.0mm; nut weights were10.20g,10.72g,10.87g,that control was10.26g; kernel rates were63.76%,64.22%,64.46%,63.02%, that controlwas63.02%; fat contents were67.18%,66.81%,67.45%, that control was66.26%.