Differences in seed vigour traits between desi (pigmented) and kabuli (non-pigmented) ecotypes of chickpea (Cicer arietinum) and its association with field emergence

Abstract

Aim: Methodology:Results: Interpretation:Pigmented (desi) and non pigmented (kabuli) cultivars of chickpea are known to differ in seed vigour. Therefore, the main objective of the study was to understand the mechanisms for such vigour differences and to identify the important seed coat and seed related vigour traits that makes the coloured desi seeds more vigorous then unpigmented kabuli seeds.Twenty two chickpea genotypes differing in seed coat colour were included in the experiment. Field emergence and electrical conductivity of seed leachate was used as vigour indicator. Hundred-seed weight, proportion of seed coat, laboratory germination, electrical conductivity, water imbibition pattern, tannin, lignin and total phenol content, presence or absence of air space between seed coat and cotyledon and status of hilum-micropylar region were studied to understand the mechanism for vigour differences between pigmented desi and unpigmented kabuli genotypes.Despite a high laboratory germination (>89%) of all cultivars, unpigmented kabuli genotypes recorded low (39-69%) FE then pigmented desi genotypes (64-87%). Rapid rate of water imbibition (111.86-145.09%), lower proportion of seed coat (4.76-6.78%), greater electrical conductivity of seed leachate (49-172 -1 µS cm g ), low content of lignin (0.74-2.41), tannin (0.18-1.09 µg mg ) and total phenol (1.66-5.58 µg mg ) was associated with low field emergence in unpigmented kabuli types. Besides, air space between seed coat and cotyledon, open hilum-micropylar region, less polyphenolic content and low proportion of seed coat potentially describe the rapid water uptake by unpigmented kabuli genotypes making them vulnerable to imbibitional damage.Rather than laboratory germination, electrical conductivity may be used as an indicator for determining field emergence in chickpea. Screening/ developing unpigmented kabuli genotypes with seeds having lower rate of water imbibition could be a promising way to enable seed vigour improvement in chickpea.

Effects of seed priming treatments on the germination and development of two rapeseed (Brassica napus L.) varieties under the co-influence of low temperature and drought

“…The priming phase contributes to the membrane repair system, by improving membrane stability, as the primed seed has a lower electrical conductivity level [ 80 ]. Related findings were obtained from sorghum seeds primed with PEG 6000 [ 4 , 81 ].…”

Effects of microscopic testa color and morphologyon the water uptake ability and drought tolerance of germination-stage rapeseed (Brassica napus L.)

“…Testa color is one of the main contributing factors of imbibition rate in a variety of crop plants, including soybean, rapeseed, wheat, and chickpea [ 11 , 16 , 35 , 36 ]. Indeed, as in the present study, previous studies have reported that the imbibition rates of black-seeded accessions are higher than those of yellow-seeded accessions [ 26–28 , 37 ].…”

Intact funiculus in mature harvested seeds of field pea (Pisum sativum L.): preliminary investigation and possible implications

“…The exact point of initial entry of water to seed during imbibition is controversial. However, the hilar–micropyle region is reported to be an initial point of entry for water in legume seeds (Chen et al., 2019; Lamichaney et al., 2017). The hilar–micropyle region is covered by the funiculus and when the seed matures, it detaches itself from the funiculus, exposing the hilar–micropyle region.…”