EFFECT OF MICROBIOLOGICAL BIOFERTILIZERS ON COTTON FIBER QUALITY AND EXPRESSION OF GENES RESPONSIBLE FOR THE TRAIT DEVELOPMENT

Abstract

Cotton is one of the most important natural fiber crops. 20% of cultivated land worldwide and 33% of irrigated farmland is subject to salinity, and this area is increasing by 10% annually. It is known that salt stress has a negative effect on all main physiological and phenotypic parameters of cotton, including the main trait - fiber quality. To reduce negative effects of salt stress on cotton, two complementary approaches are used: creation of salt-tolerant varieties and improvement of agrotechnological methods using different biostimulants. In this connection the effect of biostimulants on fiber quality parameters and expression of gens responsible for development of this trait was studied. Our studies have shown that the use of microbial fertilizers has a positive effect on fiber quality parameters. In this case the preparation Rizokom-1 had the greatest positive effect. This preparation increased one of the most important fiber quality parameters - fiber length. Besides, Rizokom-1 maximally increases fiber strength of cotton without reduction of its homogeneity index. The morphological data were confirmed by the results of expression of corresponding genes. Thus, Rizokom-1 and Micro-1 preparations significantly affected the expression level of genes responsible for synthesis of sugars (SPS and SuSy) and unsaturated fatty acids (FAD2), as well as for synthesis of cell wall polysaccharides (CESA2). The mechanism of action of the preparation Hosyl on fiber quality is mainly due to its effect on the expression level of genes regulating hormone biosynthesis involved in cotton fiber development.

Keywords

• cotton
• salt stress
• microbial fertilizers
• fiber quality
• gene expressions