Yield And Quality Formation And Regulation Of Isatis Indigotica Fort

Laboratory, Greenhouse, and field experiments were conducted to study the yield and quality formation and regulation oflsatis indigotica Fort.. The effects of Plant growth regulator DAT-6, CCC, and 6-BA on seed germination, photosynthesis, weight and chemical composition were closely examined.Seed germination experiment results indicated that seed ABA, Z+ZR, and iPA declined within 24h to 48h after initial imbibition. But, GAs reached a peak value. Seeds proteinase and amylase were activated. 96h after imbibition, more than 90% seeds turned into radicals with visible embryo root There was a peak value of Z+ZR, and iPA. The activity of seed proteinase was highest, while the amylase were increasing continuously. Plant growth regulators, DTA-6, CCC and 6-BA, were used in the seed germination experiments. The results indicated that 50mg/L DTA-6 and 40mg/L CCC accelerated the seedling growth and increased root vigor. But, 10mg/L 6-BA inhibited root growth, as well as dehydrogenase activity. 40mg/L CCC declined seed ABA, induced early GA3 peak, and increased IAA. 10mg/L 6-BA detained GA3 peak. ABA, IAA, and GA3 were decreased within 96h after imbibition. 50mg/L DTA-6 decreased ABA, but IAA . Water-soluble protein was significantly increased by SOmg/L DTA-6, and water-soluble sugar was increased by 40mg/L CCC during seeds germinating.The dynamic accumulation of I. Indigotica Fort, yield showed a "S" trend. During the late growing season, photosynthetic assimilates were mainly distributed into root. I. Indigotica Fort leaf area increased with leaf age. It reached the biggest around 20 days. At the meantime, leaf photosynthetic activities (Pn, Fv/Fm, and Fv/FO) were highest Leaf weight stopped increasing anymore after 25 day-leaf-age. Photosynthetic activities decreased. However, leaf respiration and senescence increased. Leaf indoxyl, the precursor of indigo and indirubin, presented in young leaves with highest concentration. It was declined with the leaf growth, however, the total amount were increased with the increasing weight The results also indicated mat leaf indoxyl, bom concentration and total amount, remained at the similar level after leaf reached 25 days age. The results of our experiments showed that it was best to harvest /. indigotica Fort leaf around 25 days age.50 mg/L DTA-6, 40mg/L CCC and lOmg/L 6-BA seed treatments increased Pi in elder leaf and the root vigor. The results showed that plant growth regulators increased root carbohydrate. However, other quality indexes, including indoxy and amino acids, were not significantly affected. 50mg/L DTA-6 changed the ultra structure of chloroplast and chromoplast. Plant growth regulators changed levels of plant hormones in leaf and root.