| The application of exogenous nutrient substances to regulate plant growth is an important agronomic practice in agricultural production.Oligosaccharides with high biological activity substance as a new type of plant nutrition additive,has many excellent physiological and biochemical properties.For example,promote plant growth or crop yield,improve crop quality and other biological effects.Nevertheless,development oligosaccharides as a new type of fertilizer varieties are rare at present.Meanwhile,applications of oligosaccharides are mostly limited to as plant growth regulator and antibacterial drugs.Therefore,the article mainly using the Xylo-oligosaccharides as research material,studied the Xylo-oligosaccharides effects on plant growth physiological activity and adversity resistance to salt stress,for application of the Xylo-oligosaccharides in agriculture provide theoretical basis.The Main results were as follows:1 Soil culture and hydroponic experiment were to study biological effects of Xylo-oligosaccharides on Chinese cabbage.The results showed that the Xylo-oligosaccharides spraying on the leaf and root both can increased contents of the yield,Vc,soluble sugar,soluble protein and free amino acid of Chinese cabbage to some extent.At the same time,it can also reduce the content of nitrate of Chinese cabbage,thus improved the nutritional quality of Chinese cabbage,and the best use of concentration of about 40 mg/L in both two ways.The results also show that the use of Xylo-oligosaccharides significantly increased the root growth of Chinese cabbage,and the low concentration treatment of Xylo-oligosaccharides can both significantly improve root morphology and biological activity of Chinese cabbage,but the influence of the treatment of high concentration Xylo-oligosaccharides on the root physiological characteristics of Chinese cabbage is relatively less.Meanwhile,application of the Xylo-oligosaccharides a certain concentration(40,80,120 mg/L)treatment obviously promotive effects on the absorption of N,P and K of Chinese cabbage,in addition,application of the Xylo-oligosaccharides also has certain promoting effect on the absorption of Ca Fe and Mn in Chinese cabbage root,but it can inhibition of Fe,Mn,Cu,and zinc transport to the Chinese cabbage shoot.2 Using the photosynthesis apparatus studied Chinese cabbage photosynthetic gas exchange and chlorophyll fluorescence parameters,in order to further clarify the role of Xylo-oligosaccharides to promote growth.The results show that application of the Xylo-oligosaccharides can be improved the Chinese cabbage leaf Pn,Gs,Tr and WUE to some extent,at the same time it can also significantly increase the content of chlorophyll a,and promote light system captures light pigment protein complexes and reaction centers on the absorption and transformation of energy,which is conducive to the improvement of photosynthetic rate.In addition,the Xylo-oligosaccharides treatment can also be improved the Chinese cabbage leaf Fo,Fm,Fv and q N to some extent,is helpful for plants to capture of light energy and improve the efficiency of electron transfer,moreover promoting the photosynthesis and metabolism.The Xylo-oligosaccharides treatment both can significantly increase the content of sugar and SS and SPS activity in Chinese cabbage leaf,at the same time promote the accumulation of sugar.The Xylo-oligosaccharides treatment can change sugar metabolic process and promotes the accumulation of sugar metabolites by regulate sugar metabolism enzyme activity.3 Indoor cultivation and pot experiment were to study of the effects of the organic substances Xylo-oligosaccharides on the soil properties.The results showed that application of the Xylo-oligosaccharides can be improved the soil urease,catalase and sucrase activity,at the same time it can also significantly increase the content of Soil organic carbon.Especially,largest improvement in pot experiment was xos1 and xos2 applied soil and promote the growth of soil microorganisms,which improved the soil microorganism quantity and activity,is conducive to the increase of soil microbial biomass.In addition,application of the Xylo-oligosaccharides in pot experiment can significantly increase the yield of Chinese cabbage.All the Xylo-oligosaccharides treatments were significantly increased the content of soil microbial biomass carbon and nitrogen.The increase of soil microbial biomass carbon and nitrogen to improve soil environmental quality and maintaining soil fertility is of great significance.4 Using hydroponic experiment in Chinese cabbage under salt stress adversity of the change of physiological indexes for detecting target,study the effects of the the Xylo-oligosaccharides on the growth of Chinese cabbage under salt stress.The results showed that salinity stress severely hampered the morpho-physiological growth of Chinese cabbage and disrupted the ionic balance in plant parts.Application of the Xylo-oligosaccharides increased yield of Chinese cabbage,at the same time improve the activity of antioxidant enzyme and the contents of non-enzymatic antioxidants and then increased the capacity to eliminate active oxygen.The Xylo-oligosaccharides best concentration treatments were 40 mg/L and 80 mg/L.Application of the Xylo-oligosaccharides increased the contents of osmotic-adjustment products and maintaining the ionic balance and then increased the ability of osmotic-adjustment.The Xylo-oligosaccharides treatments of three concentrations were increased photosynthesis rate,Ci and Gs in varying degrees.Therefore application of the Xylo-oligosaccharides has played a very important role in enhancing salt stress tolerance in Chinese cabbage. |
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