Effects of S-ABA on Seed Germination and Seedling Growth of Papaya (Carica papaya L.)

• Main Authors: Yuwalee Unpaprom, 尤婉琳
• Other Authors: Yau-Shiang Yang
• Format: Others
• Language: en_US
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/41630177799296718616

博士 === 國立中興大學 === 園藝學系所 === 101 === Studies on effects of natural type S-ABA on seed germination and seedling growth of papaya (Carica papaya L. cv. Tainung No. 2) were evaluated for clarify function of S-ABA. Seed germination was investigated by soaking seeds into distilled water and various concentrations of S-ABA. Percentage of seed germination in filter paper and growth medium experiments were increased by S-ABA treatments. These treatments significantly increased germination percentages (88 and 91 %, respectively) compared to control (70 and 76 %, respectively). Enhancement of germination velocity index (GVI) and seedling vigor index (VI) were obtained from treatment of S-ABA 0.01 and 0.1 ppm. While, high concentration of S-ABA (10 ppm) reduced seed germination, and resulted in abnormal germinants. However, S-ABA 1 ppm had no effect on seed germination. Young seedling stage, seedlings were treated by 2 methods of S-ABA application, foliar spray and medium supply. Results showed that S-ABA treatments increased seedling growth, especially number of leaves and roots, and fresh weight of shoot in both two application methods. Fresh weight of roots was increased by S-ABA only in foliar spray method while medium supply of S-ABA resulted in roots were small and fine. The investigation of anatomical characteristics in leaf, stem and root was supported this study. Number of palisade cell in leaf of treated seedlings was significantly increased compared to control ones. In addition, length of these cells in treated seedlings was increased but width of cell was reduced, led to leaves were dark green compared to untreated seedlings. S-ABA treatments could improve number of cell in stem and root and also increase vascular system in stem and root. Moreover, increasing in layer number of pith in stem was found from S-ABA treatments as well. Further, arrangement of cell in all three parts was more compact compared to untreated seedlings. Effects of S-ABA on nutrient and total sugar content were evaluated. S-ABA could significantly improve N and K content in all parts of seedlings, P and total soluble sugar content was increased trendily in some part of seedling. For dry weight of nutrients in whole plant, S-ABA could improve N, P, K and total soluble sugar in both two treatments of foliar spray and medium supply. Further, in 6 weeks after treatment, medium supply of S-ABA became to be more positive effect than foliar spray plants. It was found in this study that S-ABA belongs to growth promoter in tropical fruit tree, papaya. The concentration in 0.1 ppm was more effect on seedling growth and nutrient accumulation. The foliar spray of S-ABA had positive effect on leaf growth, thereafter indirectly improved stem and root growth. Moreover, the introducing of medium supply method directly enhanced root growth.