Abstract Rhizosheath formation—the adhesion of soil particles to root surfaces—has gained attention in sustainable agriculture due to its diverse contributions to plant health and productivity. This process is driven by root hairs, root exudates, and rhizosheath-associated microbial communities and shaped by plant genetics, and soil physical and chemical properties. Despite recent advances, the mechanisms underlying root–soil–microbe interactions remain poorly understood, especially in intercropping systems. Intercropping can alter belowground traits such as root system architecture, exudate profiles, and rhizosheath microbial communities, but direct links between these changes and rhizosheath formation remain unclear. We advocate incorporating rhizosheath-related traits into intercropping design to enhance crop resilience and productivity. This commentary highlights key research gaps, outlines future directions, and discusses applied perspectives for agronomy and breeding. Advancing rhizosheath biology could translate fundamental knowledge into practical innovations for sustainable agriculture.
Uniform imbibition and germination of field pea (Pisum sativum L.) seeds is very important for sprout production for human consumption. The imbibition and germination of 3 cultivars of field pea, Dunwa, Dundale, and Helena, each grown at Mullewa, Merredin, and Scaddan in the grainbelt of Western Australia, were investigated in laboratory experiments. The ability of field pea to germinate was affected by cultivar and the environment under which seed development occurred on the parent plant. Averaged over locations, germination of the cv. Dundale (82%) was lower than of Dunwa (93%) or Helena (95%). Germination of seeds ranged from 85% for those grown at Merredin to 91% at Scaddan and 94% at Mullewa. The effect of growing location on germination was most pronounced in cv. Dundale from Merredin where the largest number of hard seeds was observed. Initial seed water content was positively (r2 = 0.55*) correlated with germination across cultivars and sites. Small and large seeds within a seed lot with the same initial seed water content had a similar germination percentage. During imbibition, water entered the seed through the strophiole and this would be an appropriate place to look for a mechanism that affects imbibition. Careful selection of cultivar and favourable growing site should improve germination for the sprout producer.
Quinolizidine alkaloids (QAs) are toxic secondary metabolites found within the genus <i>Lupinus</i>, some species of which are commercially important grain legume crops including <i>Lupinus angustifolius</i> (narrow-leafed lupin, NLL), <i>L. luteus</i> (yellow lupin), <i>L. albus</i> (white lupin), and <i>L. mutabilis</i> (pearl lupin), with NLL grain being the most largely produced of the four species in Australia and worldwide. While QAs offer the plants protection against insect pests, the accumulation of QAs in lupin grain complicates its use for food purposes as QA levels must remain below the industry threshold (0.02%), which is often exceeded. It is not well understood what factors cause grain QA levels to exceed this threshold. Much of the early work on QA biosynthesis began in the 1970-1980s, with many QA chemical structures well-characterized and lupin cell cultures and enzyme assays employed to identify some biosynthetic enzymes and pathway intermediates. More recently, two genes associated with these enzymes have been characterized, however, the QA biosynthetic pathway remains only partially elucidated. Here, we review the research accomplished thus far concerning QAs in lupin and consider some possibilities for further elucidation and manipulation of the QA pathway in lupin crops, drawing on examples from model alkaloid species. One breeding strategy for lupin is to produce plants with high QAs in vegetative tissues while low in the grain in order to confer insect resistance to plants while keeping grain QA levels within industry regulations. With the knowledge achieved on alkaloid biosynthesis in other plant species in recent years, and the recent development of genomic and transcriptomic resources for NLL, there is considerable scope to facilitate advances in our knowledge of QAs, leading to the production of improved lupin crops.
Context Chickpea (Cicer arietinum L.) are highly sensitive to elevated salinity, particularly at initial seedling establishment stage. Seedling screening would be an effective means to identify novel sources of donors for salt tolerance. Aim This study aimed to identify salt stress tolerant genotypes at seedling stage from 50 chickpea accessions. Methods The screening of 50 chickpea accessions was done under two salinity conditions including salt stress (8 dS m-1) and control (no salt stress). Accessions were studied for morphological traits, root system architectural analysis, and CSTI (Cumulative salt tolerance index). Further, principal component analysis was conducted to validate these results for more accuracy and reliability. Key results For morphological traits, a high degree of genetic variation was seen among genotypes, and root traits were found to be the better indicators of salt stress tolerance. CSTI was used to classify the accessions; 22 (44%) were identified as salt sensitive, 21 (42%) were found to be moderately salt tolerant, and 7 (14%) had moderate to high salt tolerance. The most salt tolerant and salt sensitive genotypes were found to be ICCV10 and ILC5595, respectively. Conclusions Early seedling screening has a great potential to identify genotypes with robust root systems, which can withstand salinity. Implications We used a novel approach to classify chickpea landraces based on the combination of CSTI and principal component analysis methods. By choosing suitable donors and prospective genotypes at early growth stages, the knowledge gathered from this study may aid scientists and chickpea breeders in developing salt tolerant cultivars.
