Genotypic variations in root traits of wheat varieties at phytomer level

Ahk Robin,Mj Uddin,Pr Paul,S Afrin

doi:10.3329/jbau.v12i1.21238

Ahk Robin, Mj Uddin + Show 2 more

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https://doi.org/10.3329/jbau.v12i1.21238

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Abstract

The aims of this study were to investigate genotypic variations in root traits at phytomer level of wheat varieties and for recommending a few root traits as selection parameters in future breeding programs. Two separate experiments were conducted to measure their root traits for hydroponically grown wheat plants. In Experiment 1, main axis length, root hair density and diameter differed from phytomer to phytomer at 60 days after sowing for two varieties, Shotabdi and Sonalika. Density of first order laterals at their axis of origin, dry weights of roots and shoots and root:shoot ratio varied significantly among 8 varieties. In Experiment 2, number of root bearing phytomer, total number of adventitious roots, main axis length at root bearing phytomer 1 and 2 (youngest roots were the reference point and numbered as phytomer 1), length of first order laterals at phytomer 3, root hair density and dry weights of roots and shoots were significantly different among varieties. PC1 (principal component 1) resulted in significant variation among varieties for number of live leaves, new roots appeared, number of root bearing phytomer, total number of adventitious roots, root dry weight and shoot dry weight. PC2 yielded significant difference among varieties for live leaves, main axes length at phytomer 1 & 2, number of new roots, root hair density and diameter. Selection of varieties based on main axes length at the youngest phytomer & root hair density per unit surface area along with dry weights of roots and shoots could be recommended for future breeding program as these four parameters consistently resulted in significant variation among varieties. DOI: http://dx.doi.org/10.3329/jbau.v12i1.21238 J. Bangladesh Agril. Univ. 12(1): 45-54, June 2014

Highlights

Root architecture plays an important role in agricultural productivity by modifying the efficiency of nutrient uptake of the plants from the soil (Lynch, 1995)
It is reported previously that some root traits are directly related to grain yield of wheat, e.g., diameter of the roots, are directly related to harvest index and biomass at maturity (Richards and Passioura, 1989), seminal root number is strongly related to grain mass (Bengough et al, 2006) and shallow & deep root weight and root biomass are positively correlated with grain yield (Ehdaie et al, 2012)
Manschadi et al (2006) examined root system characteristics of two wheat genotypes contrasting in tolerance to water limitation and assessed the functional implications on adaptation to water-limited environments and reported that drought-tolerant wheat had a compact root system, while the standard wheat variety had a more uniform rooting pattern and greater root length at depth

Summary

Introduction

Root architecture plays an important role in agricultural productivity by modifying the efficiency of nutrient uptake of the plants from the soil (Lynch, 1995). In a few quite recent studies the importance of studying root architectural traits has been emphasized for adaptation of the crop varieties to various abiotic stress conditions. O’Toole and Bland (1987) described the significance of genotypic variation for adaptation to diverse environments and in different edaphic niches in agriculture. Manschadi et al (2008) evaluated the genotypic variability exists among 30 wheat genotypes based on root system architecture quantified through fractal analysis for drought tolerance and seminal root characteristics. Genotypic variations existed among wheat genotypes for growth angle and number of seminal roots at the seedling stage. Drought stress implications of adventitious root development and root anatomical development towards salinity resistance is described (Maggio et al, 2001; Saqib et al, 2005). Drought stress implications of adventitious root development and root anatomical development towards salinity resistance is described (Maggio et al, 2001; Saqib et al, 2005). Saqib et al (2005) reported that under saline-waterlogged conditions the development of adventitious nodal roots and cortical root aerenchyma improves Na+ exclusion and salt resistance

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