Studies On Bloom Formation On Fruit Surface Of Cucumber And The Relationship With Absorption And Distribution Of Silicon

Fruit bloom belongs to the important content of the quality of the goods. In recent years,in order to reduce the fruit surface bloom, bloomless cucumber varieties and bloomlessrootstocks were more and more inclined to choose by growers.However, the mechanism ofcucumber fruit bloom formation affected by grafting is not clear.So that,cucumber wasgrafted by different rootstocks in this study.To study the relationship of cucumber rootstocks,bloom and silicon nutrition. And discussed the formation mechanism of cucumber fruitbloom, to provide theoretical guidance for high quality cultivation and rootstock varietiesbreeding. The main results are as follows:1.‘Xintaimici’ was chosen to investigate effects of silicon content in nutrient solution onbloom formation of cucumber fruit surface and silicon distribution of own-root cucumber.Theresult showed that：At no silicon condition,there was little bloom on fruit surface.There waslow silicon content in various organs of own-root cucumber.While at silicon condition,therewas more bloom，and silicon content of different organs was increased significantly.Sothat,silicon affected formation of bloom on cucumber fruit surface significantly.2.‘Yunnan figleaf gourd’ and ‘Huangchengen No.2’ were used to graft cucumber‘Xintaimici’ to investigate effects of silicon content in nutrient solution on bloom formation ofcucumber fruit surface and silicon distribution of grafted cucumber, using own-root cucumberas the contrast.The result showed that：At no silicon condition,there were little bloom on fruitsurface and low silicon content in various organs of grafted cucumber. While at siliconcondition,the bloom on fruit surface and silicon content of different organs were increasedgrafted by ‘Yunnan figleaf gourd’.the silicon content of different organs of cucumber graftedby ‘Huangchengen No.2’ was significant lower than cucumber grafted by ‘Yunnan figleafgourd’. There was no significant different with grafted cucumber at no siliconcondition.Rootstocks removed bloom on grafted cucumber fruit was because it changedcucumber’s silicon absorption and distribution characteristics.3. Inbred line rootstocks of ‘Z1’～‘Z4’ with bloom and inbred line rootstocks of ‘Z5’～‘Z8’ without bloom on fruit surface themselves were used to graft cucumber ‘Jinyou NO.1’respectively to investigate the effects of bloom formation on cucumber fruit surface and silicon distribution of grafted cucumber,using own-root cucumber as the contrast.The resultshowed that cucumber fruit surface were bright and smooth grafted by ‘Z1’ and ‘Z2’ withbloom on fruit surface themselves.And they had no bloom almost.The cucumber fruit surfacehad much bloom grafted by ‘Z5’,‘Z6’,‘Z7’,‘Z8’ without bloom and ‘Z3’,‘Z4’ with bloom onfruit surface themselves,and there was no significantly difference compared with own-rootcucumber.There was more silicon in leaves than in roots and stem of cucumber.The siliconlevel in peel of cucumber was higher than in flesh.There was less silicon in various cucumberorgans grafted by ‘Z1’ and ‘Z2’ than the other grafted and own-root cucumbersignificantly.Grafted cucumber fruit surface had bloom or not didn’t have necessaryrelationship with quantity of bloom on fruit surface of rootstocks themselves.The cucumber’squantity of silicon absorption was Significantly reduced grafted by light-bloom rootstocks.4. The own-root ‘Xintaimici’ cucumber was Chosen to observe bloom formation processof cucumber fruit surface.During fruit growth from leaf axil (pre-flowering9d) to theflowering day (0d) is approximately10days, so development of fruit will be divided into10stages. The results show that: Along with the cucumer fruit growth, the pericarp surface areaincreases, area of bloom spheroid was gradually expanded.A gradual increase in the amountof bloom. At the same time, the process of bloom spheroid division formation was alwaysaccompanied by the precipitation of silicide.Covered the surface of bloom spheroid.5.‘Yunnan figleaf gourd’ and ‘Huangchengen No.2’ were used to graft cucumber‘Xintaimici’ to observe distribution and morphology of grafted cucumber fruit bloom,usingown-root cucumber as the contrast. The results show that:All the surface of pre-floweringyoung fruit was covered by1～2layers of intensive bloom.To the markerable mature stage,bloom spheroid interspersed among surface of fruit.There was no significant difference aboutbloom spheroid concentration. The surface of bloom spheroid was not smooth of own-rootcucumber and grafted by ‘Yunnan figleaf gourd’. It is clear to see the broken silicide aroundbloom spheroid and on their surface.While The surface of bloom spheroid was smooth andlittle silicide of cucumber grafted by ‘Huangchengen No.2’. And there was little brokensilicide on cucumber pericarp.