Advantage of Multiple Pods and Compound Leaf in Kabuli Chickpea under Heat Stress Conditions

Abstract

Heat-related traits in chickpea (Cicer arietinum L.) play a crucial role in reducing the harmful effect of heat stress, as the increase in heat stress is predicted to occur in the coming years due to global warming as a result of climate change. The advantage of multiple pods per peduncle and compound (imparipinnate) leaf traits in kabuli chickpea has not been properly revealed under heat stress conditions. We, therefore, want (i) to provide insight into the advantage of multiple pods and compound leaf traits over single pod per node and simple (unifoliolate) leaf traits, and (ii) to determine the highest direct and indirect effects of agro-morphological traits on seed yield in chickpeas under rainfed conditions with prevailing heat stress. With a delayed sowing time, the plants were subjected to heat stress of more than 43 °C in flowering and pod setting stages under field conditions. According to the number of pods per node and leaf shape, plants were evaluated for yield and yield components, and were divided into six groups, namely (i) single-pod and compound leaf, (ii) single-pod and simple leaf, (iii) double-pods and compound leaf, (iv) double-pods and simple leaf, (v) multi-pods and compound leaf, and (vi) multi-pods and simple leaf. Plants with multi-pods and compound leaf traits had the highest seed yield, followed by plants with double-pods and compound leaf, while plants with single-pod and simple leaf had the lowest yield. The number of seeds and pods per plant, 100-seed weight, and leaf shape were the highest determinants of seed yield under heat stress conditions. It was concluded that multi-pods per peduncle and compound leaf traits had an obviously incontrovertible advantage in kabuli chickpeas under heat stress conditions. The plant shapes that nature has evolved for millions of years, which are mostly found in wild plants, have been proven by the current study to have a better fitness ability than plants shaped by human hands.

Traits Related to Heat Stress in Phaseolus Species

“…Path analysis has been suggested to show direct and indirect relationships between agro-morphological traits of plants or yield components [30][31][32][33] and stress tolerance [41,77]. According to the available literature, this is the first study using the detection of direct and indirect associations between resistance to heat stress and agro-morphological traits or physiological traits using path analysis in Phaseolus species and genotypes [35].…”

“…Agglomerative hierarchical cluster (AHC) analysis with Ward's method was performed in the R statistical software and APE package Version: 5.6-2 to group bean genotypes according to their heat stress resistance level. Path analysis [34] was used to show direct and indirect relationships between heat stress resistance and the studied traits [41]. Principal component analysis based on the differences observed between the moderate heat stress and extreme heat stress conditions quantitative traits was performed using FactoMineR which is an R package dedicated to multivariate data analysis [42].…”

Herbaceous species and dry forest species have more acquisitive leaf traits than woody species and wet forest species

“…Leaf mechanical traits such as LMA (g cm −2 ), leaf thickness (LTh, mm), leaf density (LD, g cm −3 ) and leaf dry matter content (LDMC, g g −1 ) are important for the leaf defence against biophysical hazards such as herbivores, pathogens and wind, and therefore increase leaf lifespan and the duration of the photosynthetic revenue stream of the leaf (Kitajima & Poorter, 2010; Onoda et al., 2017; Poorter & Bongers, 2006). Leaf compoundness (CP, 0 = simple, 1 = compound) is related to leaf(let) size and heat balance of the plant (Eker et al., 2022), while leaf deciduousness (DE, 0 = evergreen, 1 = deciduous) allows plants to avoid dry season drought (Poorter et al., 2021). Traits were measured following standardized protocols (Pérez‐Harguindeguy et al., 2013).…”

“…At the other side of the leaf size spectrum long petioles allow them to forage for light and avoid self-shading (Niinemets, 2007;Poorter & Rozendaal, 2008) and large LAs can increases light interception (Falster & Westoby, 2003), while compound leaves often have small photonastic leaflets that may fold at noon to cope with heat and drought stress, especially during the dry season (Eker et al, 2022). We found similar spectra (size and leaf economics), both in the dry and wet forest, as Díaz et al (2016) in a global analysis of 46,085 species belonging to different life forms.…”

Physiological Responses of Chickpea Genotypes to Cold and Heat Stress in Flowering Stage

“…In contrast to the physiological performance of the other three genotypes, Fv/Fm and PN of Acc#7 were significantly reduced under heat stress, accompanied by decreased gs and E compared with control, indicating that Acc#7 is a heat-sensitive candidate. Sudden heat-stress application (45 °C) let to defoliation, leaf drying and flower abortion in early-flowering and pod-setting chickpeas, resulting in low yields [34]. All tested chickpea genotypes significantly reduced the chlorophyll a+b contents in their leaves under heat stress, showing their sensitivity to the heat stress application.…”