Xenia Effects On Yield And Fruit Quality Of Blueberry

In recent years,blueberries have become popular with consumers because of their attractive flavor.Therefore,This paper is aiming to breed blueberry cultivars with excellent fruit quality and rich nutrition.However,There is few research on the xenia of blueberry.In this paper,eight kinds of blueberry cultivars from Zhejiang Province were used as materials.Firstly,the paper used serveral methods to analyzed the compatibility among various combinations,such as: measuring fruit setting rate,observing pollen tube growth,counting the paternal proportion in the offspring seedlings,then carried out the comprehensive evaluation of blueberry cultivars by measuring fruit quality and using principal component analysis(PCA).Finally,the paper analyzed the effect of xenia on fruit setting rate and fruit quality of blueberry.The main results are as follows:1.The FDA-PI staining methods were used to detect the pollen vitality,it was found that the pollen vitality of different cultivars was higher than 50%,and it had good fertility.The availability of the stigma was examined on the day of flowering and 1d,2d and 3d after flowering,and the results showed that the stigma was active.Artificial self-pollination was used as the control,and eight kinds of pollen were pollinated for ‘Emerald’ and ‘O’neal’.It was found that the fruit setting rate was significantly different among all the pollination pairs,which was caused by xenia phenomenon.When ‘Emerald’ was the produced cultivar,the fruit pollinated with ‘Gulfcoast’?‘Bluerain’ got the highest fruit set ratio which was over 65%.When ‘O’neal’ was the produced cultivar,the fruit set ratio of ‘O’neal’בBluerain’ was the highest about 72%,while ‘Misty’ pollen contributed the lowest setting rate both.2.Taking self-pollination as the control,This paper compared the germination rates of pollen tubes to determine the compatibility of different cross combinations.The study found that after 48 hours of pollination,the pollen tubes of ‘Misty’ got twistled when they reached at the middle of ‘Emerald’’s stigma.What’s more,there was a large amount of callose deposition appeared at the end of ‘Misty’’s pollen tubes,which blocked the pollen tubes growing further and resulted in the failure of fertilization,then the difficulty in getting fruit afterward.On the other hand,the fertilization process of ‘Bluerain’ pollen was successful because of the tube reaching the ovlue in 24 hours after pollination,indicating that ‘Bluerain’ had wide compatibility with ‘Emerald’ and ‘O’neal’.This result is in accordance with the fruit setting ratio analysis,which is ‘Bluerain’ pollination got the higher fruting ratio for both pollinated cultivars.3.Microsatellite markers were used for parentage analysis to indentify more than 200 samples,which was pollinated by eight mixed pollens.When ‘Emerald’ was the produced cultivar,‘Emerald’ × ‘Gulfcoast’ had the largest number among the seedlings,the proportion was 37%;when ‘O’neal’ was the produced cultivar,‘O’neal’בBluerain’ had the most offspring,accounting for 28% of the total samples.This result was consistent with the information of the fruiting ratio sequence from field experiments,which once again showed that there was a positive correlation existed between the pollen competition and the fruit setting rate.4.Xenia phenomenon had a significant effect on the fruit character of blueberry which affected the fruit quality,transverse and vertical diameter of fruit,hardness,soluble solids concentration,anthocyanins concentration,titratable acid and soluble sugar concentration.The results showed that: ‘Emerald’ had the best physical traits,‘O’neal’ had the best fruit nutrients.According to the comprehensive evaluation index,when ‘Emerald’ was the produced cultivar,comprehensive texture quality of ‘Gulfcoast’ and ‘Bluerain’ were much better than other varieties;when ‘O’neal’ was the produced cultivar,comprehensive texture quality of ‘Jewel’ and ‘Gulfcoast’ were much better than other varieties.In summary,blueberry has the xenia effect on fruit.In order to improve fruit setting rate,‘Bluerain’ can be used as the best pollinated cultivar for ‘Emerald’ and ‘O’neal’,which may be related to the pollen competitive adventage and the compatibility of pollen to stigma.However,mechanisms of the specific interaction between pollen and stigma need further research.Meanwhile,plant ‘Gulfcoast’、 ‘Jewel’ nearby to produce higher yield and bigger or sweeter fruits.