Studies On The Mechanism Of Heat Injury And Heat Adaptation And Summer Cultivation Techniques Of Cucumber(Cucumis Sativus L.)

CucM (Cmis satns L.) is a twrtan vegetabe in Chha boy,the mechasm of cuCUInber cold injury and cold tolrm w nded in detail,hoWven the mechedsm of cucumber heat injmp and hea tolere alW hav lessattention. N of cucumber's setaltrOpic origin. But in faCk hea thes in summcan W cucUInber growth and preduction severely in the ndddie and south China,so it is wt tO stud the meebosm of cucUI'nbe hot injmp and hod tOleranCe,as well as CUCUmber surnmer culhvatiOn teCtws.There are sighfiCan heat-oleran differece axnong the -- lines.Some Wsms are involved in tha one genotype is mere hea tOle!an thananother in one speies, l avoidance. 2 higher mdslism hod tObo. 3 higherboration ability aller hca stress. Therefore, which IneChanis are taken byheaboltal cucumber genotyPes? There are diffend heat toleran methods indtherent cucumber ecOtyPes or not? StUdy thOse PrOblems mp Provide some theclues fOr tw heaboleran variCties or itw summ Wation teCtw offorCUCUInber"s oUtPut organ is tender fhat. So hea tOlew of cucUmber'srePreduCtion Systems is a key factoI to effeCt sumxner cUCUInbe culhvation. However,as a regreL there is few detailed rePOrt on hea injmp and hca toleranee ofcucumboreproduction systems recently. According to primary obseIvation in field, less boeflowers and acceleraed senescence process are twrtan meons of yteld reduConin suxnmer cucutnber cLilhvation, but SChOlars seldom we attention to themecbostns of ti1ose Phenomena.Earier StUdies showed aPpling some chdrital reagend or Plants growthregUlatOrs can PrOInote CUCUInber heat tolerance. The forque of tw cucUInboonto SqUaSh (Cucurbita ficifolia Bouche) hav alread been POpulaha in whcucUmber culhvation because Squash root Sydems have Stronger cold tOleranee,absorption ability and soil-bome diseases resistanCe than cUCUInbe root SyStems.Therewith, it is pessible the eding tecndque will Promote cucUInber hea tOlmein the field. So in this Pmpr, hea tOletal methOds of diforot cucUInbe eCOtyPeS,physiological IneChanism of hea injny and hea tolerance ofcuctnnhe reProduChonsystems, cucumber high temperatUre protection agentS and sununer pe cucumberculhvation teCboques were stUdied. The resultS shoWed tha:l Different cucM lines have different hea-toleran Inethods in yteld fOedon.Under high temperatUre, comParing with hea sensihve line ki-ci, EP-6 hevehigher feInale node rate and ParthenOCarpic thet set rate, XC-l hav more plantnode IUnnbe and higl1er staInen and pollen hea toleranee, and NY-l hav slightadW in all aSPectS abOve.2 Cucumber StaInns are more sensitive to high temperatUre than pinils. 40C or 35'C is suitable to distinghsh POllen heat tolerance of differen cucumber lines,estifnated by gennination rae or pollen tube length repehvely If Stamens orpistils of cucumber lines are treated by high temperatUr 3h per day in 2 daysbefore Wsis, 35t is sLtitable to distinghsh StarnenS hea tolean of differentcucumber lines, crihtal temPeratUre of styles injmp is about 4045'C, and criticaltempeW of ovedes injury is about 45-50'C. Different hca tOhaance of pistilsamong cucumber lines was not found in mis study.3 High temperatUr treatment at seeding stage can reduce more cucumber productionthan hatInnt at fruit setting sIage. During the seedling Stag l0 to 50 days aftersowin, the earier cuctunber seedlings are hated by high tempewt, the moreyield lose.4 The most sensitive stage tO lhgh temperata in male and femaie flowerdevelopment is l2-6 days before anthsis. Different cucumber lines have sedlarmale flowe bud length but different femaie flower bud length in each deVloPmenStagrs. Relative bud length may be a creditable index to deduce feInale flowerdeveloPment Stags.5 In aPical point of cuctnnber Stems, higher endogenous ethene evolution and lowespm content can accelerate senescenee process, and high endogenous Pu and GA3contents can promote Inale flower differentiation. High tempewt acceleratesenescence process and r...