Study On Salt Tolerance Of Different Apple Rootstocks In Their Offspring

This experiment uses the progeny of Malus baccata(Linn)Borkh.,Malus prunifolia(willd.)Borkh.,SH,Malus royalty,North American Begonia,and Malus asiatica Nakai as test materials(all of which are Malus baccata(Linn)Borkh.Malus prunifolia(willd.)Borkh.,SH,Malus royalty,North American Begonia,Malus asiatica Nakai replace the actual offspring),with 0.25%,0.50%,0.75%,1.00% NaCl solution as the stress treatment.Through the determination of its mortality,growth indicators,physiological and biochemical indicators,photosynthetic parameters,mineral elements,and used in fuzzy mathematics The membership function evaluation method comprehensively analyzed the salt tolerance of different rootstocks,and explored the damage mechanism of different concentrations of NaCl solution on apple plants,which provided a theoretical basis for the screening of local salt-tolerant rootstocks.The results are as follows:(1)Under NaCl stress,the mortality of each tested plants increased with the increase of salt concentration.The growth of plant height and the growth of stem diameter decreased with the increase of stress concentration,and the survival time of Malus prunifolia(willd.)Borkh.during treatment was better,at 1.00% concentration,there are still plants with better survival,and the plant height and stem diameter are better after the treatment.The Malus baccata(Linn)Borkh.is more seriously damaged.The plant height and stem growth of Malus royalty were relatively good,while the plant height growth of SH and the stem growth of Malus asiatica Nakai were relatively small,indicating that the stress on the plant height and stem diameter of Malus royalty was relatively small,and the effect on SH and Malus asiatica Nakai was relatively large.(2)Under salt stress,the physiological indexes of the tested plants varied greatly with the increase of stress concentration,but with the prolongation of stress time,malondialdehyde content,soluble sugar content,soluble protein content,SOD activity,POD activity and CAT activity.The upward trend and the proline content showed a downward trend.Combined with the above physiological indicators,the comprehensive evaluation of the tested plants showed that the salt tolerance of Malus prunifolia(willd.)Borkh.and Malus royalty was better,and the salt tolerance of Malus baccata(Linn)Borkh was the weakest.(3)With the increase of salt concentration,the changes of chlorophyll b content and total chlorophyll content were basically the same;under 1.00% concentration of salt stress,the chlorophyll content of Malus asiatica Nakai leaves was lower than that of the control,while the other tested plants were slightly larger than the control.At 1.00% concentration,the rootstock leaves Pn,Gs,Tr and Ci except for the Malus royalty decreased,indicating that the reason for the rise of the Malus royalty leaf Ci may be due to non-stomatal limiting factors.(4)With the increase of salt stress,the contents of N,Cl and Na in the tested plants increased,and the change of Na content in Malus prunifolia(willd.)was the smallest;the contents of K,Ca and K/Na,Ca/Na decreased.The contents of P and B in the leaves of Malus baccata(Linn)Borkh.,SH and Malus royalty.mandshurica decreased significantly.The contents of Fe and Cu in the leaves of Malus royalty.mandshurica decreased significantly.(5)According to the membership function analysis of each tested plants,the order of salt tolerance is as follows: Malus prunifolia(willd.)Borkh.>Malus royalty>North American Begonia >Malus asiatica Nakai>SH>Malus baccata(Linn)Borkh.Based on the above conclusions,it is concluded that the salt-tolerant ability of Malus prunifolia(willd.)Borkh.is stronger and more suitable for local planting.