Context. Preservation of genetic diversity of species is a pressing issue; in particular, the preservation of the gene pool of many rare and endangered plants is a priority. Species of the genus Crambe (family Brassicaceae) have potential in agriculture and bioremediation.

Aims. This study aims to assess the genetic diversity and DNA fingerprint of five rare species of the genus Crambe, and to develop the concept of a genetic passport for rare plants.

Methods. DNA fingerprinting was conducted via the inter simple sequence repeat (ISSR) method, using six ISSR primers. Hierarchical cluster analysis of the species was performed.

Key results. In total, 145 polymorphic loci were detected. The studied species formed two different clusters on genetic dendrogram analysis. The first cluster comprised two species, Crambe steveniana and C. tataria from a single subsection (Tatariae), forming a common clade. They were the most genetically close species with genetic similarity of 0.8431. The remaining three species (C. cordifolia, C. maritima, C. pinnatifida), from another subsection of Crambe, formed nodes from the general clade.

Conclusions. The findings allow plants to be genetically certified using our methods and informative ISSR primers for rare plants. We were able to propose a genetic formula identifying a species and present an example of a genetic passport for rare plants. The genetic structure of C. pinnatifida was investigated for the first time.

Implications. The present findings contribute to the systematics and critical investigation of rare plant species with genetic resource potential. A genetic passport could be used in the protection of copyright of agricultural varieties.

Context. Food security, integral to the UN sustainable development goals, has become a global priority. Only a handful of cultivated species meet 80% of dietary intake, and hence, in future, it may be inadequate to depend only on these crops.

Aim. Wild germplasm is endowed with desirable traits of relevance to food, health and climate resilience and, hence, there is a need to intensify efforts for bringing wild edible plants into mainstream agriculture. Wild banana (Ensete spp.) is a staple food source besides having bioactive compounds, nutraceuticals and cosmeceuticals.

Methods. Ensete species are cultivated in Asian and African countries, and its cultivation through superior clones is done through conventional methods and plant tissue culture techniques. Despite information on the ecological, social and economic features of Ensete spp., there has been no systematic assessment of their nutritional and other agronomic traits.

Key results. Herein, we provide a comprehensive account of Ensete sp. conservation, domestication, nutritional profile and medicinal importance as well as documenting the biotechnological approaches and identifying research gaps and prospects of these underutilised species.

Conclusion and implications. We believe this review could form a baseline resource to aid decision-making for improvement of the crop towards sustainable use and domestication of the species in the global context.

Context. Broadening the gene pool of staple food crops by incorporating desirable genes from wild/relative species is way to achieve higher genetic gains. The African rice species Oryza glaberrima Steud. is a source of genes for genetic improvement of Oryza sativa L. to various biotic and abiotic stresses.

Aim. The study was undertaken to identify genomic regions associated with yield and yield-related traits in interspecific backcross mapping populations derived from variety IR64 (O. sativa indica) × O. glaberrima.

Methods. The BC₁F₂ and BC₁F_2:3 populations were phenotyped for days to 50% flowering, plant height, number of tillers, number of productive tillers, panicle length, spikelet fertility and grain yield under irrigated conditions. The BC₁F₂ population was genotyped with 99 genome-wide polymorphic SSR markers. Quantitative trait loci (QTLs) associated with yield-enhancing traits were identified through single marker analysis.

Key results. Significant genetic variability was observed with moderate to high heritability in mapping populations. Genotyping revealed the presence of segregation distortion and skewed genome composition. Single marker analysis identified 20 QTLs linked to the studied traits. A QTL linked to grain yield, qGY-4.1, derived from O. glaberrima was found in both populations with high phenotypic variance. The chromosome region around marker RM510 was identified as a QTL hotspot and putative candidate genes were identified.

Conclusions. Our study demonstrates that O. glaberrima can serve as a valuable genetic resource for genetic improvement of yield-enhancing traits in O. sativa cultivars.

Implications The identified QTLs regions can be employed in molecular breeding. The promising introgression lines identified can be used as pre-breeding lines in future breeding programs.

Context. Post-anthesis heat stress is a major concern for wheat. Stay-green (SG) can serve as a crucial marker for plant adaptation to it. Though genetic resources provide an invaluable gene pool for crop breeding, collections are still uncharacterised and their potential is yet to be explored.

Aim. This study was planned to characterise and evaluate wheat genetic resources, including wild germplasm, for heat stress tolerance using SG traits as selection criteria.

Methods. Experiment was conducted with thirty wheat genotypes under late and very late sown environments for 2 years. Genotypes were assessed for SG traits like Normalised Difference Vegetation Index (NDVI), Soil Plant Analysis Development Chlorophyll Meter Reading (SCMR), Leaf Senescence Rate (LSR), chlorophyll fluorescence (F_v/F_m), canopy temperature (CT), phenological traits, morphological traits, yield and its attributes; and characterised into three categories viz., slow senescing, intermediate senescing and fast senescing, based on their rate of senescence.

Key results. Results indicate that slow-senescing genotypes had a significantly higher NDVI, SCMR and yield as compared to fast-senescing genotypes. NDVI, SCMR, F_v/F_m, days to heading, days to anthesis, days to maturity, grain weight per spike, 100-grain weight and biomass were significantly positively correlated whereas LSR and CT were significantly negatively correlated with grain yield. From the principal component analysis studies, it was revealed that genotypes with a high SCMR, a low LSR, and a high grain yield were placed together as SG genotypes.

Conclusions. This study confirms that genotypes with SG traits performed better under heat stress.

Implications. From the wild, genotypes HTW 11 (W), HTW 67 (W) and HTW 6 (W) can be utilised for heat tolerance breedings.

Context. Agronomical traits like loss of seed dispersal targeted by ancient human selection are an important milestone of crop domestication. Evolution in plant species is a result of natural and human selection at the time of domestication. Evolution leads to continued improvement of adaptive traits in almost all plant species.

Aim. Pod shattering, one of the examples of convergent evolution, is defined as breaking up of the pod shell enabling the successful dispersal of seeds mainly in wild species. Since the available climate change models predict an increase in aridity, it is expected that the losses on account of shattering will be aggravated, especially in dry areas.

Methods. Histological studies and biochemical parameters are increasingly used as surrogates for pod shattering response as they provide key inputs for selecting contrasting genotypes based on differential lignification, role of pectin, fibre, cellulose and total carbohydrate content as well as enzymes such as endopolygalacturonase and β-glucanase and hormones.

Key results. There is diversity for level of shattering, with race Nueva Granada showing higher rates of pod shattering as compared to the Durango and Jalisco races. Genomics has helped identify several genes or quantitative trait loci (QTL) such as PDH-1, St-1, SHAT-1, WRKY1 and MYB26 that are implicated in various traits related to pod shattering.

Conclusions. Plant breeders need to introgress shattering resistance into commercial varieties to mitigate the imminent yield losses.

Implications. This requires an in-depth knowledge of mechanistic, physiological, biochemical and the underlying genetic basis of pod shattering resistance.

Context. Cultivation of quinoa (Chenopodium quinoa Willd.) is rapidly expanding worldwide. Characterisation of populations of Chenopodium hircinum Schard., its wild ancestor, which thrives in some of the hottest environments in South America, may provide adaptations to new environments.

Aim. This study evaluated the developmental patterns of populations of C. hircinum collected from a range of agroecological environments in Argentina, in order to quantify variability among sites of origin and to explore the association between climatic data from environments of provenance and variation in development.

Methods. Thirty-three populations of C. hircinum from contrasting sites of origin in Argentina were multiplied in a common-garden experiment under non-limiting conditions of water and nutrient availability. Plants were sampled once or twice weekly (according to parameter) for estimation of the duration of developmental phases, leaf number, and dates of initiation of branching on the main stem.

Key results. Significant variation was detected for all phenological traits, and populations were categorised into six groups based on similarity of patterns of variation. We found positive association of the duration of development phases and the number of leaves on the main-stem with maximum temperature during the growing season, and negative association with altitude of origin, consistent with variation in growing-season duration.

Conclusions. The finding that late-flowering populations are associated with warmest climates reveals that longer vegetative growth is an adaptive strategy to cope with heat stress in Chenopodium spp.

Implications. Time to flowering should be considered in attempts to improve quinoa performance under heat-stress conditions. Further work is needed to understand the genetic basis controlling this response in wild populations of C. hircinum.

Climate change and global warming are the foremost anthropogenically accelerated catastrophes that are already causing world-wide challenges, but threaten to thwart global food, environmental and nutritional security in the future. Climate change affects ecosystem services and interactions between biotic and abiotic factors. The most drastic consequences have been observed in the agricultural and livestock sector, with diminished production and productivity potential. Agriculture and allied sectors contribute markedly to the production of greenhouse gases; however, integrated management practices can be used to curtail greenhouse gas emissions and its adverse impacts. Forage crops and their wild relatives maintain biodiversity and ecosystem services and minimise the drastic effects of climate change. Forage crops adapted to harsh environments have certain unique features such as perenniality, deep root system, high resource-use efficiency (light, nutrients and water), and low production of methane and N₂O, making them suitable for future use under climate change. This review highlights the prominent features of various cultivated and rangeland forage crops that may be crucial to understanding impacts of climate change. We discuss the wild relatives of forage crops, which are often adapted for multiple stresses, and highlight their mechanisms for adaptation under climate change. We consider the advanced breeding and biotechnological tools useful for developing climate-smart forage crops. This review provides novel insight into forage crops and their wild relatives in terms of their exploitation in future stress breeding programmes and paths for developing climate-resilient crops.

Since the Bronze Age, oat (Avena sativa L.) has been used mainly as an animal feed. Currently, it is in high demand for human consumption because of its nutritional properties, which improve health and wellbeing. Oat is a good source of protein, carbohydrates, lipid, minerals, vitamins and phenolic compounds. However, quality traits are usually polygenic and subjected to non-heritable factors, making quality improvement difficult. Several conventional breeding approaches such as pure line selection, pedigree selection, mutagenesis, wide crosses and polyploidy have been extensively used to develop new and improved oat varieties, commonly for forage purposes. Molecular approaches such as use of molecular markers, QTL mapping, genome-wide association studies, genetic engineering, genomic selection and speed breeding are being utilised to identify traits/genes of interest, produce plants carrying the desired agronomic and climatic resilience traits, and accelerate genetic gain. There has been minimal focus on nutrient enrichment and the development of high-quality, enriched oat genetic resources. Herein, we address and compile much-needed, up-to-date information on comparative analysis of oat nutritional and phytochemical properties with those of other cereals. We also consider the importance and involvement of conventional breeding in the modern approaches. This updated information provides guidance for oat breeders to develop nutrient-enriched varieties and points to future prospects towards oat quality improvement.

Content. Knowledge about genetic variability parameters is imperative for improving crop plants for traits of economic importance. This paper reports the characterisation of a large germplasm set of an underutilised pseudocereal Buckwheat endemic to northwestern Himalayas in order to elucidate the nature of variability as well as identify trait specific genotypes for use in buckwheat breeding programmes.

Aim. The major aim was to estimate the genetic variability of yield and related traits in diverse germplasm lines of buckwheat collected from different regions of the north-western Himalayas.

Methods. The material was evaluated in a randomised complete block design with five replications at two different locations in SKUAST-K, Shuhama and MAR & ES Izmarg, Gurez, during the years 2020 and 2021. For assessing diversity patterns, the clustering of the germplasm from both locations was done by Tocher’s method.

Key results. The results indicated significant variability in the buckwheat germplasm for all morphological traits across locations. The phenotypic cofficient of variation and genotypic coefficients of variation (PCV, GCV), broad sense heritability and genetic advance values varied between locations. Pooled across locations, the highest PCV values were recorded for number of primary branches. Heritability ranged from low for number of secondary branches to medium for days to 50% flowering.

Conclusion. The present study provided valuable insights about the variability and trait diversity in buckwheat germplasm under Northwestern Himalayan conditions.

Implications. The information on variability parameters can be harnessed to develop an effective breeding strategy for improving buckwheat for traits of economic interest.

Climate change impacts crop production through the imposition of different abiotic and biotic stresses, and by altering the prevalence of pests and diseases. The wild relatives of crop plants exhibit enhanced tolerance to environmental stresses due to reduced severity of selection of agriculturally important traits. Wild bananas represent a largely untapped wealth of genetic diversity. Although some wild relatives of the banana crop have been screened for their tolerance to different biotic and abiotic stresses, many remain to be explored. The wild bananas show more hardiness and higher resilience to different stressors in comparison to their cultivated counterparts. They have been harnessed in banana improvement programmes to enhance stress tolerance and productivity. To utilise wild bananas for crop improvement, they need to be readily available to breeders. This warrants devising conservation strategies and the development and maintenance of centres from which different accessions can be procured. In this article, we have discussed some important biotic and abiotic stresses including banana wilt disease, Black Sigatoka disease, viral diseases, salt stress and drought stress where wild bananas are used for imparting tolerance. The conservation of wild bananas, related challenges and contemporary limitations related to their use for crop improvement has also been outlined. Bananas being most important food crop in the world and generally understudied, here, we present a comprehensive review of the use of wild relatives of banana and their related germplasm for the improvement of biotic and abiotic stress tolerance.

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.

Context. Under natural field conditions, plants confront the co-occurrence of stresses. A comprehensive insight into combined-stress tolerance is requisite to developing stress resilience in cultivars of oats (Avena sativa L.) for saline–alkaline soil.

Aim. This study was undertaken to characterise diverse oat genotypes for seedling growth attributes under two saline and alkaline concentrations and under combined saline–alkaline conditions.

Methods. We screened 105 accessions of the genus Avena with the following treatments: control, reverse osmosis water; moderate salinity (50 mM); high salinity (100 mM); moderate alkalinity (15 mM); high alkalinity (30 mM); combined moderate salinity–alkalinity (50 mM + 15 mM); and combined high salinity–alkalinity (100 mM + 30 mM). For saline treatments, NaCl and Na₂SO₄ salts were used in equimolar concentrations, and for alkaline treatments, NaHCO₃ and Na₂CO₃.

Key results. Analysis of variance showed significant (P ≤ 0.001) variation among treatments and genotypes. Principal component analysis revealed 83.3% of the total genetic variation accounted for in the first two principal components. Correlation analysis showed a significant positive correlation between final germination percentage and seedling vigour index. Stress tolerance index identified tolerant and sensitive oat genotypes under high saline and alkaline stress, and multi-trait stability analysis confirmed the stability of performance of some genotypes under the imposed treatments.

Conclusions.According to the stress tolerance index and multi-trait stability analysis, genotypes IG-20-477, OS-377, IG-20-798 and IG-20-575 were found suitable for high saline–alkaline stress.

Implications.The identified tolerant oat genotypes can be used as donors for the development of stress-resilient oat cultivars, and for generating mapping populations in oat.