Genetic variability of drought-avoidance root traits in the mini-core germplasm collection of chickpea (Cicer arietinum L.).

Abstract

SummaryExtensive and deep root systems have been recognized as one of the most important traits for improving chickpea (Cicer arietinum L.) productivity under progressively receding soil moisture conditions. However, available information on the range of variation for root traits is still limited. Genetic variability for the root traits was investigated using a cylinder culture system during two consecutive growth seasons in the mini-core germplasm collection of ICRISAT plus several wild relatives of chickpea. The largest genetic variability was observed at 35 days after sowing for root length density (RLD) (heritability, h 2 = 0.51 and 0.54) across seasons, and followed by the ratio of plant dry weight to root length density with h 2 of 0.37 and 0.47 for first and second season, respectively. The root growth of chickpea wild relatives was relatively poor compared to C. arietinum, except in case of C. reticulatum. An outstanding genotype, ICC 8261, which had the largest RLD and one of the deepest root system, was identified in chickpea mini-core germplasm collection. The accession ICC 4958 which was previously characterized as a source for drought avoidance in chickpea was confirmed as one with the most prolific and deep root system, although many superior accessions were also identified. The chickpea landraces collected from the Mediterranean and the west Asian region showed a significantly larger RLD than those from the south Asian region. In addition, the landraces originating from central Asia (former Soviet Union), characterized by arid agro-climatic conditions, also showed relatively larger RLD. As these regions are underrepresented in the chickpea collection, they might be interesting areas for further germplasm exploration to identify new landraces with large RLD. The information on the genetic variability of chickpea root traits provides valuable baseline knowledge for further progress on the selection and breeding for drought avoidance root traits in chickpea.

Traits of relevance to improve yield under terminal drought stress in chickpea (C. arietinum L.)

“…This genotype showed the highest CGR among the entries (3.13 g m -2 day -1 ), and fairly low WUE till early reproductive stage indicated by the second highest Δ 13 C as 20.4‰. In a previous report, ICC 7571 had been shown to possess a larger root biomass ranking the top 16 th among the chickpea mini-core germplasm collection which comprise 216 diverse chickpea genotypes (Kashiwagi et al, 2005).…”

“…Compared to most other legumes, root system of chickpea is known to be well adapted for growing under receding soil moisture conditions by possessing more number of thin xylem vessels facilitating effective, less energy-requiring soil moisture absorption (Purushothaman et al, 2013). Also in chickpea, a large genetic diversity has been reported on the root biomass as well as rooting depth, and promising genotypes were also identified (Kashiwagi et al, 2005). Though the heritability of the rooting depth was not high enough meriting consideration for breeding, the root biomass and root length density does merit (Kashiwagi et al, 2008a).…”

“…Also, the recently documented existence of a large diversity for root biomass, root prolificacy and rooting depth in chickpea mini core germplasm accessions (Kashiwagi et al, 2005), encourages efforts of improvement through enhanced absorption.…”

Improving Drought-Avoidance Root Traits in Chickpea (Cicer arietinumL.) -Current Status of Research at ICRISAT

“…A minicore collection (n=211) of chickpea germplasms was developed at ICRISAT (Upadhyaya and Ortiz, 2001), and it was evaluated for root traits using the cylinder culture system subsequently. Large and significant variation was found among the accessions of the minicore collection for root length density (RLD), root dry weight (RDW), rooting depth (RDp) and root to total plant weight ratio (R/T) (Kashiwagi et al, 2005). The signifi cant genotype × season interaction that occurred for RLD and R/T in this study was found to be of noncrossover type.…”

Quantitative Analysis of Induced Phenotypic Diversity in Chickpea Using Physical and Chemical Mutagenesis

“…Kashiwagi et al (2006Kashiwagi et al ( , 2005 and Reynolds and Tuberosa (2008) in chickpeas viewed that deep and prolific root system contributes directly to productivity under water limited conditions. Number of primary branches per plant increased only in 200 Gy (15.9228) while in all other treatments it decreases compare to control (14.3166) and 0.04% HZ (7.2083) inhibited maximum.…”