不同砧木嫁接的赤霞珠葡萄对盐胁迫的生理响应

Physiological responses of Cabernet Sauvign seedlings grafted on different salt-tolerant rootstocks to NaCl stress

为阐明不同砧木嫁接对葡萄的影响及为建立葡萄耐盐性评价体系提供理论依据,以赤霞珠葡萄为接穗品种、分别以耐盐砧木101-14,耐盐性中等的贝达,盐敏感的砧木188-08和5C为砧木,以赤霞珠葡萄自根苗为对照,研究幼苗对不同浓度(70、100、130和160 mmol/L)NaCl胁迫的生理响应差异。结果表明:盐胁迫下,所有试材叶片叶绿素含量、净光合速率(Pn)、气孔导度(Gs)、胞间CO2浓度(Ci)、蒸腾速率(Tr)等指标随NaCl浓度增加而逐渐降低;无盐处理条件下,赤霞珠葡萄嫁接苗叶片中超氧化物歧化酶(SOD)和过氧化物酶(POD)活性均显著高于自根苗,而脯氨酸(Pro)含量低于自根苗;在NaCl胁迫条件下,赤霞珠嫁接组合各生理指标的变化因砧木耐盐性的不同而产生明显的差异,耐盐性强的101-14嫁接的赤霞珠叶片中丙二醛(MDA)和Pro增幅最小,SOD和POD维持较高的活性,根系具较强的拒Na+能力,通过根系向地上部分转运K+以增加叶片中K+含量,从而抵御盐离子对叶片的毒害作用,调节植株体内离子平衡,而其他砧木贝达、188-08、5C嫁接的赤霞珠虽然叶片中SOD和POD活性显著增加,但根系拒Na+和对K+的选择性吸收的能力不强,不能通过嫁接改善赤霞珠的耐盐性。

The study aimed to clarify the effect of different rootstocks grafting on grapevine salt tolerance.Based on the salt-tolerance identification of a series of grape rootstock varieties,the grape cultivar‘Cabernet Sauvign’were grafted on different salt-tolerant rootstock varieties‘101-14’,‘188-08’,‘5 C’and‘Beta’to investigate seedlings’physiological responses to NaCl stress.Four concentrations of NaCl were conducted.The results showed that chlorophyll,net photosynthesis rate(Pn),stomatal conductance(Gs),intercellular CO2 concentration(Ci)and transpiration rate(Tr)were significantly decreased with the increase of salt concentration.Leaf soluble sugar contents and peroxidase(POD),superoxide dismutase(SOD)activities of the grafted seedlings were significantly higher than those of the self-rooted seedlings.Whereas the leaf proline contents of the grafted seedlings were significantly lower than those of the self-rooted seedlings under non-salt treatment.Under the salt stress,the physiological response of four scion/rootstock combinations and the self-rooted seedlings were significantly different.Leaf proline and malondialdehyde(MDA)content of the grafted seedlings were significantly lower than those of self-rooted seedlings,and the seedlings grafted on‘101-14’showed the lowest MDA content.The POD and SOD activities of the grafted seedlings were significantly higher than those of the self-rooted seedlings,and the POD and SOD activities were the highest for the seedlings grafted on‘101-14’.The seedlings of the Cabernet Sauvign scion/101-14 combination displayed lower Na+content in leaves and better alternative transportation of K+under salt stress.Although the activities of SOD and POD in the leaves of Cabernet Sauvign grafted on other rootstocks such as Beta,188-08 and 5 C increased under salt stress,the ability of root system to resist Na+and selectively absorb K+were weak.Therefore,these three rootstocks didn’t improve the salt tolerance of Cabernet Sauvign by grafting.