| It is a global problem that Apple is facing continuous cropping obstacles.The methods and ways to alleviate and overcome Apple's continuous cropping obstacles are the urgent issues to be solved.In this study,combined with the causes of severe dysentery,the authors started with the breeding of resistant heavy-bred rootstocks.Eight kinds of apple rootstocks obtained from in-situ breeding in the previous period were used as test materials,and Malus hupehensis Rehd.served as a control,and they were resistant to continuous cropping of apple rootstocks.Conduct the test.The effects of continuous cropping soil on the physiological indexes of disease severity index,relative chlorophyll content,photosynthetic fluorescence parameters,antioxidative enzyme activity and root vigor of different apple rootstocks were studied.In addition,in order to ensure resistance to rootstocks,the selected apple rootstocks with resistance to heavy pods were selected for tissue culture techniques for propagation and rooting in order to explore suitable light quality and suitable auxin species for rooting of apple rootstocks in vitro.concentration.In the experiment,a set of apple resistant rootstock screening and breeding technology system was established by resistance tes ting and rapid propagation of tissue culture to provide reference for the breeding of apple rootstocks.1.The disease index of leaves of apple rootstocks superior lines was analyzed under continuous cropping obstacles.The resistance degree was E2-23 and Malus hupehensis Rehd.as high resistance,31,2-11 middle resistance and 12-2BJ disease resistance.2-7,2-1,19 and L24 are more severely affected,and the promotion value needs further exploration.2.Differents apple rootstocks superior lines were tested for resistance to the continuous cropping obstacles,and E2-23,12-2BJ,31 and 2-11 showed good resistance to heavy pods,among which 12-2BJ,31 and 2-11 had significant chlorophyll content.Compared with Malus hupehensis Rehd.,Malus hupehensis Rehd.increased by 11.42%,15.11% and 6.62% respectively in September.The root vigor of 12-2BJ,31 and E2-23 was stronger.The aboveground growth and photosynthetic fluorescence parameters of the plants were significantly better than those of Malus hupehensis Rehd..The activities of SOD,POD and CAT were better than Malus hupehensis Rehd.in different degrees.3.The study of different LED light qualities on the subculture of apple rootstock tissue culture seedlings found that blue light has a significant role in promoting the differentiation of apple rootstock tissue culture seedlings,can shorten the incubation period,increase the propagation coefficient,and cultivate high-quality strong seedlings.The red light reduces the proliferation coefficient,reduces the relative content of chlorophyll,and then inhibits the growth of tissue culture seedlings to preserve.4.In the rooting test of tissue culture seedlings treated with different concentrations of auxin,all three auxins showed low concentration promotion and high concentration inhibition on the rooting of apple rootstock tissue culture seedlings.The sensitivity of plants to NAA was greater than that of IAA and IBA.Therefore,the rooting methods of IAA and IBA were rooting directly in root dermis,and the rooting rate and survival rate of transplanting were all higher.NAA was rooting of callus,but the rooting rate was high but the survival rate of transplanting was higher.Very low.The number of IAA rooting was small,but the root growth rate was fast,and the root coefficient increased first and then decreased with increasing concentration.The total root length,surface area and total volume of the root were treated with 0.7 ppm IAA.The IBA 0.7 ppm treatment has more root tips,thicker roots,but slower root growth.In a comprehensive analysis,IAA 0.7 ppm is the optimal hormone concentration for rooting of apple rootstock tissue culture seedlings. |
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