高温对不同厚皮甜瓜品种种子萌发的影响及其耐热性综合评价OA北大核心CSTPCD

[Objective]To study the effect of high temperature on the germination of thick skin melon seeds and the differences in high-temperature tolerance among different thick skin melon varieties in the hope of providing theoretical basis for the selection of more high-temperature resistant thick skin melon varieties and the seedling management and promotion application of thick skin melon.[Methods]Five main thick skinned melon varieties in Xinjiang with different heat resistance,Nasmi,Huangpi 9818,Xinmi 14(Xin-hongxincui),Huangmengcui and Kalakesai(Jiashigua),were used as test materials,and treated at 4 temper-atures(28(CK),35,40 and 50℃).The germination potential,germination rate,germination index and ac-tivity index of thick skinned melon seeds at the germination stage were compared.Superoxide dismutase(SOD)The activities of peroxidase(POD),Catalase(CAT),Malondialdehyde(MDA)and proline(Pro)contents were studied.[Results]The seeds of 5 thick skinned melon varieties were able to germinate and grow normally at 28℃,and the germination was relatively neat;At 35℃,muskmelon seeds could germinate faster,but excessive germination led to overgrowth and uneven growth;At 40℃,the germination effect of seeds was similar to that of 35℃,with slight inhibition of growth and acceleration of elongation,but not e-nough to distinguish the differences in heat resistance among varieties;At 50℃,the germination of melon seeds was delayed,and the embryonic roots gradually decayed after germination.The high-temperature inhi-bition effect was significant,and there was a significant difference in germination ability between strains.At 50℃,the antioxidant enzyme activity of varieties with good heat resistance increased,while the antioxidant en-zyme activity of varieties with poor heat resistance decreased.SOD and POD played a greater role than CAT,and the increase in MDA was inversely proportional to heat resistance,while the increase in proline was direct-ly proportional to heat resistance.[Conclusion]The five thick skin melon varieties can be divided into two different heat tolerance levels:heat resistant and heat sensitive.The heat resistant types are Huangmengcui and Nasimi;Heat sensitive type:Huangpi 9818,Xinmi 14,Kalakesai.Three thick skinned melon varieties(Huangmengcui,Nasimi,Huangpi 9818)bred through cross breeding have better heat resistance during seed germination than the other two typical Xinjiang melon landraces(Xinmi 14,Kalakesai).