Comparative Study Of The Physiological Characteristics On Drought Resistance In Different Apple Rootstock-scion Combinations

In this experiment,the experiment was carried out at the Northwest A & F University in 2016.The grafts of M9 Interstock,M26 Interstock and M26 self-rooted rootstock were used as the experimental materials,and the scion was the same(Nagafu 2).The effects of different rootstocks on the growth,physiological characteristics and root activity of Fuji apple were studied.The test set three levels of treatment: 75%-80% of the control group,moderate stress(MS)of 45%-50% and severe stress(SS)35%-40 %.With the increase of water stress and the extension of time,the differences and dynamic changes of morphological indexes,physiological indexes and biochemical indexes were determined.The results showed that the growth of lateral shoots,plant height growth,stem growth,leaf water potential,MDA content,chlorophyll,net photosynthetic rate,stomatal conductance,transpiration rate and root activity.Through the determination of these indexes,the physiological characteristics of three kinds of apple and apple were analyzed.The results are as follows:1.The results showed that the leaf water potential decreased with the increase of drought stress,and the water potential of drought-poor scionstock combination was low and the descending rate was relatively large,and the decrease of water potential was more obvious.Water sensitivity is more sensitive.2.In this experiment,it was found that the MDA content in the leaves increased with the increase of drought stress under drought stress,and the drought resistance with different scionstock combination was relatively good.3.The results showed that the effects of drought stress on chlorophyll content were different in different degrees.Under the moderate stress,the total chlorophyll content increased first and then decreased,and the total chlorophyll content continued to decrease after heavy stress,indicating that heavy drought stress Destruction of the chloroplast structure,the more drought-resistant rootstock varieties,with the drought stress intensified,the smaller the change in chlorophyll content.4.Under the drought stress,the net photosynthetic rate(Pn),stomatal conductance(Gs)and transpiration rate(Tr)of different scionstock combination were decreased with the increase of drought stress,and the decrease of photosynthetic parameters increased with the increase of drought stress And increase.The more drought-resistant scionstock combination,the smaller the decline.5.The root vigor can represent the strength of root metabolism,which is very important to the growth and stress resistance of the plant.From the experimental results,the root activity decreases with the increase of drought stress.The drought resistance of the rootstock was better than that of drought resistance.6.A comprehensive analysis of the three kinds of apple scionstock combination of form indexes under drought stress,changes in physiological and biochemical indicators of its ability to tolerate drought stress sorting,M26 Interstock best drought resistance,M9 Interstock followed,M26 self-rooted rootstock's drought resistance was the worst.