Chapter 1 - Physiological and environmental control of adventitious root formation in cuttings: An overview

Abstract

In plants, the adventitious roots are mainly produced from the leaves, hypocotyls, stems, or shoots. They are highly useful for vegetative propagation (or clonal propagation). In this propagation technique, various types of stem cuttings are used especially in forestry and in horticulture practices. Adventitious root formation (ARF) in stem cuttings is controlled by several exogenous and endogenous factors. ARF in stem cuttings is quite often divided into physiological and metabolic markers. The main factors that control ARF are auxin, maturation, genotype, explant position, irradiance, temperature, water availability, season, mineral nutrition, rooting conditions, proliferation medium, and so on. The identification and use of correct combination and/or auxin treatment have improved the stem rooting potential, even in hard-to-root species. Auxin treatment to stem cuttings causes metabolic changes during the ARF, which consists of three successive but independent phases, namely induction, initiation, and expression. Further, using the cutting-edge tools of genome and proteome analysis, some notable suggestions have been proposed to understand molecular regulations, genes, and cellular processes involved in ARF. Considering these crucial points, it is essential to understand the underlying factors and also their interactions during ARF in stem cuttings. Therefore, in this chapter, the prime focus is on the developmental processes, and physiological and environmental control of ARF in shoot/stem cuttings.