Carbohydrate Accumulate And Adventitious Root Formation At The Stem Bases Of Solanaceous Vegetable Cuttings

Solanaceous vegetables,including tomatoes,peppers and eggplants,are the main vegetable species grown worldwide.Cutting propagation is commonly used for rapid propagation,grafting,and germplasm resource preservation of solanaceous vegetables.In this paper,tomato variety 'Zhongza 302',pepper variety 'Zhongjiao No.6' and eggplant variety 'yuanza 471' were selected as test materials.The effects of seedling age on adventitious root formation at the stem bases of tomato,pepper and eggplant cuttings were determined.The change characteristics of carbohydrate content at the stem bases of tomato,pepper and eggplant cuttings were revealed.The synthesis of photosynthetic products was changed by removing the true leaves of tomato seedlings,confirmed that carbohydrate accumulation at the stem bases promotes adventitious root formation of solanaceous vegetables.It provided a reference basis for the regulation of adventitious root formation in solanaceous vegetables cuttings.The main results are as follows:1.The adventitious root formation at the stem bases of tomato,pepper and eggplant seedlings at2-leaf stage,3-leaf stage and 4-leaf stage was comparatively analyzed.It was found that adventitious roots in tomato cuttings had the earliest occurrence,the largest number,and the longest total length,followed by peppers and eggplants.The increase of seedling age delayed the time of adventitious root occurrence of eggplant cuttings;the number of adventitious roots was the most in tomato and eggplant cuttings at 3-leaf stage and pepper cuttings at 4-leaf stage;the total length of adventitious roots was the longest in tomato cuttings at 3-leaf stage and pepper and eggplant cuttings at 2-leaf stage.The above shows that there are significant differences in the adventitious root formation at the stem bases of tomato,pepper and eggplant cuttings.The age of seedlings significantly affects the adventitious root formation at the stem bases of tomato,pepper and eggplant cuttings.2.The carbohydrate content at the stem bases of tomato,pepper and eggplant cuttings was determined.It was found that the content of glucose,fructose,sucrose and total soluble sugar at the stem bases of tomato,pepper and eggplant cuttings showed an increasing trend with the passage of time after cutting,the starch content was relatively stable,and the hexose/sucrose ratio increased rapidly to the peak at the early stage of cutting.Correlation analysis showed that adventitious root formation was significant positively correlated with the contents of glucose,fructose,sucrose and total soluble sugar in tomato and pepper.The above shows that the accumulation of soluble carbohydrates at the stem bases is closely related to the formation of adventitious roots in solanaceous vegetables cuttings.3.The method of removing leaves from tomato seedlings was used to reduce the synthesis of photosynthetic products,and the carbohydrate content,related enzyme activities and relative gene expression levels at the stem bases of tomato cuttings were measured during adventitious rooting.The results showed that leaf-removal changed the encoding gene relative expression level and activity of carbohydrate unloading enzymes SUS and CWIN,significantly reduced the accumulation of glucose,fructose,sucrose and total soluble sugar,and inhibited adventitious root formation.The results showedthat the accumulation of carbohydrates at the stem bases promotes adventitious root formation,and keeping appropriate number of leaves is beneficial to the formation of adventitious roots in tomato cuttings.