Differences in salt alkali stress response and tolerance between two melon varieties during bud seedling stage

WANG Ting; WANG Yuzhou; WANG Mengke; LI Lu; ZHANG Kun; FANG Zhigang

doi:10.16861/j.cnki.zggc.2024.0402

Abstract：Melon varieties of Lürou Jiashigua and Xikaixin were used as materials,50 mmol·L-1NaCl and NaHCO3 salt were used to simulate mild neutral salt,alkaline salt,and mixed salt-alkaline salt(NaCl∶NaHCO3=1∶1,1∶2,2∶1),respectively,to clarify the physiological characteristics of two melon varieties in response to saline-alkali stress during the bud and seedling stage. The results showed that saline-alkali treatment significantly affected seed germination index,α amylase activity,phenotypic parameters of seedling roots(root surface area,root length,root diameter)and respiratory inten-sity. Under alkaline salt treatment alone,seed germination rate,germination potential,germination index,seedling roots length,seedling dry mass,and α-amylase activity were the lowest,the seedling respiration was the highest,root cell mem-brane damage was severe,and multiple indicators of Xikaixin were significantly higher than those of Lürou Jiashigua. The seed germination index,seedling dry mass,root length,and α-amylase activity decrease with the increase of alkaline salt ratio in the treatment solution. Under the treatment of mixed saline-alkali threat(NaCl∶NaHCO3=1∶2),the dry mass and root length of the Xikaixin seedlings were significantly higher than that of lürou Jiashigua. In summary,alka-line salt stress has a greater degree of harm to the germination and seedling growth of melon seeds than neutral salt and mixed salt alkali stress. The two varieties were equally tolerant to neutral salt during bud and seedling stage,and Xikaixin was more resistant to mixed saline and alkaline salt stress than that of lürou Jiashigua. Increasing the proportion of neutral salt in the treatment solution can appropriately improve the adaptability of melon sprouts to salt alkali stress during the bud and seedling stage.