Study On The Indentification Technique System Of Heat Tolerance And Anther Gene Expression Under Heat Stress In Capsicum Annuum L.

Two pepper(capsicum annuum L.) strains CV.B35and CV. B6were used as test materialsfrom Genetic breeding research group of the Northwest Agriculture and Forestry University,College of Horticulture, the identification system of heat tolerant pepper by using thedetached leaf was established, and this system was proved applicable; by using The screenedheat-resistant strain CV. R9and thermal strain CV. B6，we studied the physiological responseof pepper under high temperature stress，and further identified the auxiliary indicator whichcan be used to screen heat tolerant pepper; by using cDNA-AFLP technique，we identified thedifferentially expressed genes during meiosis on strains CV. R9and CV. B6under hightemperature stress the main results are as follows:1. Identification system of pepper heat tolerance by using detached leaves(1) The sample to the flask by interpolation to be immediately placed in a38°C underlight incubator processing3000to4000lx light, continuous light treatment60h, Statisticsheat injury index to identify the heat resistance of the pepper strains(2) the injury artificially divided into nine degree:0-whole leaf green, no heat injury symptoms1-water loss, mild wilting3-mild chlorosis, mild wilting5-the overall leaves yellowish and wilting, partial tip necrosis7-Whole leaf yellowish, tip necrosis, leaf margins rolled9-whole leaf yellowish and necrosis scorch, leaf margins rolled(3) Heat injury index=∑(at all levels of heat injury index number of leaves×the heatdamage level value)÷(the survey total number of leaves×value)×100;(4) The heat resistance identification methods as follows:Heat injury index≤35.0resistant strains;Heat injury index35.1-59.9medium-resistant strains;Heat injury index≥60.0for the thermal strains.This method in pepper strains MC4MIT0LEE SELN-1,83-2018-2, yellow Marshal Department of the2nd choice, jade selected lines, the full sub pepper and Early Calwonder(both cited in the development of the Asian Vegetable Research Center) were verified.2. The growth and physiological response to high temperature stress of different heatresistance of pepper seedlings and the screening of heat identification index.The results showed compared with normal temperature, seedling height, fresh weight inroot and shoot, dry weith in root and shoot as well as seedling index were significantlydeclined in both heat-resistant CV. R9and heat-susceptibleCV. B6under heat stress. But theeffects on CV. B6were more severer than CV. R9. Besides, high temperature also increasedthe proline contents in both cultivars, but the magnitude inCV. R9was more bigger than thatof theCV. B6. Both SOD and POD activity were showed a trend of first increased and thendecreased, but the heat-resistant variety was higher than the heat-susceptible variety, whereasthe malondialdehyde content in CV. R9was below the CV. B6.3. By using cDNA-AFLP technique, we conduct the analysis of expression response tohigh temperature stress of different heat-resistant pepper stamens, The results showed overall62differential bands were obtained, of which23were cloned and sequenced,6of them in theheat-resistant strain CV. R9-specific expression,3specific expression in the thermal strainsCV. B6,6in heat-resistant strains CV. R9upregulated and8upregulated in the thermal strainsCV.B6, high-temperature stress-induced genes involved in energy metabolism andbiosynthesis, adversity response, transcriptional regulation, signal transduction, etc.. Thisexperiment has laid a foundation for pepper heat resistance.