Title : Study of the effects of growth regulators on the growth and rooting of grape apical meristem in vitro
Abstract:
Apical meristem is a set of cells that divide rapidly and thus cause faster growth. Apical meristem cells at the shoot and roots, are used to grow plants faster that generate stem during the shoot ontogeny. These cells currently deserve high attention to develop uninfected plants. The growth from apical meristem requires suitable nutrient medium containing plant growth regulating hormones. N6-benzyladenine (BA) and 2,4-dichlorophenoxyacetic acid (2,4-D) were reported efficient to produce axillary and adventitious shoots in seedlings. The best combination of these phytohormones was found among different options. The tandem of 6-benzylamino purine (BAP) and 5-naphthalene acetic acid (NAA) was demonstrated as another efficient choice with Murashige and Skoog (MS) basal medium. The most efficient concentration of these chemicals for shoot multiplication was found among different options. That’s why we were tested more different growth regulators and mediums in our experiments. So the addition of meta-topolin, naphthaleneacetic acid, and supramolecular complex in 0.5: 1: 0.17 mg/L doses, respectively, increased the assimilation of ammonium nitrate in WPM nutrient media and enabled to reduce of its quantity in the medium four-fold. But the addition of 10 mg of sucrose was required for the revealed efficiency of the modified MS nutrient medium. These differences in WPM nutrient media were even greater. The addition of 0.17 mg/L supramolecular complex of glycyrrhizic and salicylic acids and 0.25 mg/L of benzylaminopurine resulted in several-fold effects with the twice-lower quantity of all used ingredients.The highest effects of the modified nutrient media were observed with those explants taken in May and April. The ones, taken in August and September, did not reveal efficiency with both MS and WPM nutrient media. In December, January and February, the plants growing in nutrient media stopped the growing, and the appearance of new shooting started in March and April. The effects of the complex on the number and length of roots of four grape varieties, widely grown in Uzbekistan, showed its potential as a root growth regulator. The complex in 0.15 and 0.17 mg/L doses together with benzylaminopurine in MS medium or with meta-topolin and naphthalene acetic acid in WPN culture media led to several-fold increases in root growth in all grape varieties in vitro. The effects of the complex at 0.15 mg/L dose resulted in at least twice longer root length of all selected grape varieties compared to control of both culture media. A higher 0.17 mg/L dose led to several-fold increases in root length. Besides, significant increases were observed in root numbers in explants, grown in a culture medium holding 0.17 mg/L of the complex. In this work, we reported the effectiveness of 0.17 mg/L of the supramolecular complex of glycyrrhizic and salicylic acids with 0.25 mg/L BAP in MS medium, and with 0.48 mg/L meta-topolin and 0.1 mg/L naphthaleneacetic acid in WPM nutrient media. Further improvement in this discipline will enable the enhancement of the cost-efficiency of the modified nutrient media.
