Effects Of Carbonized And Fermented Crumbs Of Apple Branches On The Growth Of Apple Plants,Root Transcriptome And Soil Nitrate Metabolism

A large number of pruned branches are discarded in the orchard every year, which are potential resources. The fermented or carbonized crumbs of apple branches recycling and reuse in the farmland can not only avoid wasting resources and polluting our environment,but also generate additional economic benefits, which is the effective way of developing circular agriculture. Apple trees(Malus hupehensis Rehd.cv.Fuji) and seedling rootstock Malus hupehensis(Pamp.) Rehd. var. pinyiensis Jiang were used as materials in the experiment. The effects of fermented and carbonized crumbs of apple branches on plant photosynthetic characteristics, root characteristics and nitrate metabolism in root zone soil were investigated. In addition, the transcriptome of part of the roots were analyzed. The results show that:1. The results showed that the rate of leaf net photosynthetic, root activity and increment of trunk girth of apple plants were increased after applying the fermented crumbs of apple branches to the soil in the mass fraction of 2%, 4% and 8%, and there was no obvious effect on leaf transpiration rate and water use efficiency. The number, surface-area,volume, length, diameter and fractal dimension of new roots were all increased and the root structure was more complex after the application of 2% fermented crumbs of apple branches.The growth of root was restrained after the application 4% of fermented crumbs of apple branches and the root became shorter and thicker. The comprehensive analysis shows that the effects of application of 2% dosage on the growth of root and trunk were better than that of 4% and 8% as a whole.2. The results showed that the rate of leaf net photosynthetic and transpiration,chlorophyll content and root activity were increased after applying the carbonized crumbs of apple branches to the soil in the mass fraction of 0.5%, 1%, 2% and 4%, and there was no obvious effect on leaf intercellular carbon dioxide concentration and stomatal conductance.The application of 4% carbonized crumbs of apple branches significantly restrained the activity of phenylalanine ammonia and polyphenol oxidase in root, but there was no significant impact when the application was below 4%. The comprehensive analysis showed that the effects of application 1% dosage on the photosynthetic characteristics were betterthan that of 0.5%, 2% and 4% as a whole. The application of 4% of the carbonized crumbs of apple branches had a negative risk on the growth of apple plant.3. 17.32 Gb clean data were obtained by means of high throughput sequencing technology platform of Illumina HiSeq? 2500, and each of the samples obtained more than5.52 Gb clean data. There were 4648 differentially expressed genes, of which, 4332 genes were up-regulated after applying carbonized crumbs of apple branches to the soil in the mass fraction of 1%. And there were 2735 differentially expressed genes, of which, 1591 genes were up-regulated after applying fermented crumbs of apple branches to the soil in the mass fraction of 2%.4. The carbonized crumbs of apple branches obviously influenced the leakage of nitrate in the orchard soil. The volume of leakage liquid decreased with the increase of the amount of carbonized crumbs of apple branches. The volume of leakage liquid which carbonized crumbs of apple branches were applied to the soil in the mass fraction of 4% is less than that of others. The utilization rate of nitrogen were increased after applying carbonized crumbs of apple branches to the soil.