Foxtail millet performance under low phosphorus (P) is determined by growth potential, with tiller number as a key indicator. Yield is influenced by P dilution rather than total P concentration. Foxtail millet, renowned for its high nutrient content and drought resilience, faces limited breeding investment despite being cultivated in vulnerable agri-systems. Low phosphorus (P) levels affect approximately 50% of global agricultural soils, and particularly impact regions like Sub-Saharan Africa and Southeast Asia, the latter where foxtail millet is extensively grown. This study explores the effects of low P (< 5 ppm; Hedley Fractionation Method; Cross and Schlesinger 1995) on foxtail millet plant growth and yield-related traits, utilizing high-throughput platforms (HTP) with a selected subset of genotypes (n = 10) from the core collection of ICRISAT Genebank. Results uncover substantial variation in plant growth and agronomical traits at both treatment and genotype levels. Under low-P conditions, genotypic variation is noted, with a sixfold difference in tiller count, 2.4-fold in grain yield, 2.7-fold in 3D-leaf area, and 2.3-fold in root surface area. A significant relationship was found between grain yield under low-P and high-P conditions (R2 = 0.65; P < 0.01). This suggests that genetic yield potential (vigor) under high-P conditions strongly influences grain yield and tiller numbers under low-P conditions. Residual grain yield under low-P conditions, not explained by high-P conditions, had a strong positive association with tiller numbers (R2 = 0.70; P < 0.01) and showed a significant negative association with total P concentration (R2 = 0.54; P < 0.05). Conversely, under high-P conditions, grain yield (GY_LF) from Lysi-Field exhibited significant positive correlations with P use efficiency (PUE) (r = 0.94; P < 0.001) and total biomass (r = 0.84; P < 0.01). These findings underscore the critical role of P availability in influencing grain yield and related traits. Under low-P conditions, performance is primarily driven by growth potential, with tiller number serving as a reliable marker of this potential. The significant genotypic variation observed highlights the importance of selecting for growth-related traits in P-limited environments. In addition, P dilution, rather than total P concentration, appears to play a key role in determining yield under low P. Optimizing P management strategies and breeding for improved growth potential may significantly enhance crop performance in regions facing P limitation.

• Klíčová slova
• Foxtail millet, Grain P content, High-throughput phenotyping platforms, Nutrient deficiency, Phosphorus stress, Phosphorus use efficiency, Resource poor soil,
• MeSH
• biomasa MeSH
• fenotyp MeSH
• fosfor * metabolismus   MeSH
• genotyp MeSH
• půda chemie   MeSH
• Setaria (rostlina) * růst a vývoj   genetika   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fosfor * MeSH
• půda MeSH

Nutrient and water limitations contribute to yield losses in semi-arid regions. Therefore, crop rotations incorporating nitrogen-fixing legumes and drought-tolerant sorghum varieties offer a strategy to improve the utilization of scarce soil resources. Under semi-arid, field-like conditions, sorghum crop rotations with either cowpea pre-crop or fallow, including two early and three late maturing genotypes, were tested to identify stress adaptation traits of sorghum to water and phosphorus limitations. Morphological and physiological parameters were evaluated on a single-plant basis. Lower soil P content significantly delayed flowering compared to higher P levels. However, improved P availability arising from pre-crop residues reduced this effect. Mycorrhizal infection rates and root-to-shoot ratios were positively correlated with panicle N and P content at anthesis under low P conditions. Although drought significantly impacted yield, early maturing genotypes with the highest reduction in shoot biomass and reduced water use before flowering, could sustain yield production. Early-maturing genotypes characterized by high root-to-shoot ratios, rapid AMF establishment, and reduced water use before flowering exhibit a strong potential for maintaining yield and biomass production on nutrient-poor soils in semi-arid regions. Such genotypes conserve water before flowering and thus can alleviate post-flowering water stress, ensuring adequate P uptake despite low soil P availability.

• Klíčová slova
• Drought, Multiple resource limitations, Phosphorus, Plant phenological development, Sorghum, Water use,
• MeSH
• biomasa MeSH
• dusík metabolismus   MeSH
• fosfor * metabolismus   MeSH
• genotyp MeSH
• kořeny rostlin metabolismus   růst a vývoj   MeSH
• mykorhiza MeSH
• období sucha * MeSH
• půda * chemie   MeSH
• Sorghum * růst a vývoj   metabolismus   genetika   fyziologie   MeSH
• voda * metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• dusík MeSH
• fosfor * MeSH
• půda * MeSH
• voda * MeSH

Transpiration efficiency (TE), the biomass produced per unit of water transpired, is a key trait for crop performance under limited water. As water becomes scarce, increasing TE would contribute to increase crop drought tolerance. This study is a first step to explore pearl millet genotypic variability for TE on a large and representative diversity panel. We analyzed TE on 537 pearl millet genotypes, including inbred lines, test-cross hybrids, and hybrids bred for different agroecological zones. Three lysimeter trials were conducted in 2012, 2013 and 2015, to assess TE both under well-watered and terminal-water stress conditions. We recorded grain yield to assess its relationship with TE. Up to two-fold variation for TE was observed over the accessions used. Mean TE varied between inbred and testcross hybrids, across years and was slightly higher under water stress. TE also differed among hybrids developed for three agroecological zones, being higher in hybrids bred for the wetter zone, underlining the importance of selecting germplasm according to the target area. Environmental conditions triggered large Genotype x Environment (GxE) interactions, although TE showed some high heritability. Transpiration efficiency was the second contributor to grain yield after harvest index, highlighting the importance of integrating it into pearl millet breeding programs. Future research on TE in pearl millet should focus (i) on investigating the causes of its plasticity i.e. the GxE interaction (ii) on studying its genetic basis and its association with other important physiological traits.

• MeSH
• biomasa MeSH
• genetická variace MeSH
• genotyp * MeSH
• období sucha MeSH
• Pennisetum * genetika   fyziologie   růst a vývoj   MeSH
• šlechtění rostlin metody   MeSH
• transpirace rostlin * fyziologie   MeSH
• voda metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• voda MeSH

'QTL-hotspot' is a genomic region on linkage group 04 (CaLG04) in chickpea (Cicer arietinum) that harbours major-effect quantitative trait loci (QTLs) for multiple drought-adaptive traits, and it therefore represents a promising target for improving drought adaptation. To investigate the mechanisms underpinning the positive effects of 'QTL-hotspot' on seed yield under drought, we introgressed this region from the ICC 4958 genotype into five elite chickpea cultivars. The resulting introgression lines (ILs) and their parents were evaluated in multi-location field trials and semi-controlled conditions. The results showed that the 'QTL-hotspot' region improved seed yield under rainfed conditions by increasing seed weight, reducing the time to flowering, regulating traits related to canopy growth and early vigour, and enhancing transpiration efficiency. Whole-genome sequencing data analysis of the ILs and parents revealed four genes underlying the 'QTL-hotspot' region associated with drought adaptation. We validated diagnostic KASP markers closely linked to these genes using the ILs and their parents for future deployment in chickpea breeding programs. The CaTIFY4b-H2 haplotype of a potential candidate gene CaTIFY4b was identified as the superior haplotype for 100-seed weight. The candidate genes and superior haplotypes identified in this study have the potential to serve as direct targets for genetic manipulation and selection for chickpea improvement.

• Klíčová slova
• Cicer arietinum, Chickpea, drought stress, haplotypes, introgression lines, legume, marker-assisted backcrossing, transpiration efficiency, whole-genome sequencing,
• MeSH
• Cicer * genetika   MeSH
• genomika MeSH
• Publikační typ
• časopisecké články MeSH