The germinations of three common buckwheat (Fagopyrum esculentum) varieties and two Tartary buckwheat (Fagopyrum tataricum) varieties seeds are known to be affected by high temperature. However, little is known about the physiological mechanism affecting germination and the effect of melatonin (MT) on buckwheat seed germination under high temperature. This work studied the effects of exogenous MT on buckwheat seed germination under high temperature. MT was sprayed. The parameters, including growth, and physiological factors, were examined. The results showed that exogenous MT significantly increased the germination rate (GR), germination potential (GP), radicle length (RL), and fresh weight (FW) of these buckwheat seeds under high-temperature stress and enhanced the content of osmotic adjustment substances and enzyme activity. Comprehensive analysis revealed that under high-temperature stress during germination, antioxidant enzymes play a predominant role, while osmotic adjustment substances work synergistically to reduce the extent of damage to the membrane structure, serving as the primary key indicators for studying high-temperature resistance. Consequently, our results showed that MT had a positive protective effect on buckwheat seeds exposed to high temperature stress, providing a theoretical basis for improving the ability to adapt to high temperature environments.

The cultivated peanut (Arachis hypogaea L.) is a significant oil and cash crop globally. Hundred-pod and -seed weight are important components for peanut yield. To unravel the genetic basis of hundred-pod weight (HPW) and hundred-seed weight (HSW), in the current study, a recombinant inbred line (RIL) population with 188 individuals was developed from a cross between JH5 (JH5, large pod and seed weight) and M130 (small pod and seed weight), and was utilized to identify QTLs for HPW and HSW. An integrated genetic linkage map was constructed by using SSR, AhTE, SRAP, TRAP and SNP markers. This map consisted of 3130 genetic markers, which were assigned to 20 chromosomes, and covered 1998.95 cM with an average distance 0.64 cM. On this basis, 31 QTLs for HPW and HSW were located on seven chromosomes, with each QTL accounting for 3.7–10.8% of phenotypic variance explained (PVE). Among these, seven QTLs were detected under multiple environments, and two major QTLs were found on B04 and B08. Notably, a QTL hotspot on chromosome A08 contained seven QTLs over a 2.74 cM genetic interval with an 0.36 Mb physical map, including 18 candidate genes. Of these, Arahy.D52S1Z, Arahy.IBM9RL, Arahy.W18Y25, Arahy.CPLC2W and Arahy.14EF4H might play a role in modulating peanut pod and seed weight. These findings could facilitate further research into the genetic mechanisms influencing pod and seed weight in cultivated peanut.

Cultivated Peanut (Arachis hypogaea L.) is an important oil and cash crop in worldwide. Hundred pod and seed weight are important components for peanut yield. In order to dissect the genetic control of hundred pod weight (HPW) and hundred seed weight (HSW), a RIL population containing 188 individuals was developed from a cross between Jihua 5 (JH5, large pod and seed size) and M130 (small pod and seed size). An integrated genetic linkage map was constructed by using SSR, AhTE, SRAP, TRAP and SNP markers. The map contained 3,130 genetic markers which were assigned to 20 chromosomes and covered 1,998.95 cM with an average distance 0.64 cM. Based on the genetic map, a total of 31 QTLs for HPW and HSW were identified on 7 chromosomes, explaining 3.7-10.8% of the phenotypic variation by each QTL. Among these, seven QTLs were detected under more than two environments, two major QTLs were found on B04 and B08, respectively. A QTL hotspot containing seven QTLs was detected on chromosome A08 spanning a 2.74 cM genetic interval with 0.36 Mb physical map which included 18 candidate genes. Among these, Arahy.D52S1Z, Arahy.IBM9RL, Arahy.W18Y25, Arahy.CPLC2W and Arahy.14EF4H may be involved in regulating peanut pod and seed weight. These results may help further analysis of genetic mechanisms for pod and seed size in cultivated peanut.

F-box proteins are a large gene family in plants, and play crucial roles in plant growth, development, and stress response. To date, a comprehensive investigation of F-box family genes in peanuts, and their expression pattern in lateral branch development has not been performed. In this study, a total of 95 F-box protein family members on 18 chromosomes, named AhFBX1-AhFBX95, were identified in cultivated peanut (Arachis hypogaea L.), which were classified into four groups (Group I–IV). The gene structures and protein motifs of these peanut FBX genes were highly conserved among most FBXs. We found that significant segmental duplication events occurred between wild diploid species and the allotetraploid of peanut FBXs, and observed that AhFBXs underwent strong purifying selection throughout evolution. Cis-acting elements related to development, hormones, and stresses were identified in the promoters of AhFBX genes. In silico analysis of AhFBX genes revealed expression patterns across 22 different tissues. A total of 32 genes were predominantly expressed in leaves, pistils, and the aerial gynophore tip. Additionally, 37 genes displayed tissue-specific expression specifically at the apex of both vegetative and reproductive shoots. During our analysis of transcriptome data for lateral branch development in spreading and erect varieties, namely M130 and JH5, we identified nine deferentially expressed genes (DEGs). Quantitative real-time PCR (qRT-PCR) results further confirmed the expression patterns of these DEGs. These DEGs exhibited significant differences in their expression levels at different stages between M130 and JH5, suggesting their potential involvement in the regulation of lateral branch development. This systematic research offers valuable insights into the functional dissection of AhFBX genes in regulating plant growth habit in peanut.

Pod and seed traits are important agronomy traits, which are closely related to yield in cultivated peanut (Arachis hypogaea L.). In the present study, to identify molecular markers closely linked to pod and seed traits, a RIL₈ population with 315 families was developed that derived from Jihua 5 with large pod and M130 with small pod of US germplasm. A genetic linkage map containing 363 polymorphic loci was constructed using SSR, AhTE, SRAP, and TRAP markers. All polymorphic loci were mapped on 21 linkage groups, which spanned 1360.38 cM with an average distance of 3.75 cM. Subsequently, a total of 97 QTLs for pod and seed traits were identified by ICIM method at five environments from 2017 to 2018, explaining the phenotypic variations of 2.36%–12.15% , and located on A02, A05, A08, A09, B02, B03, B04, B08, and B09 chromosomes. Among them, nine QTLs were detected for pod length, 13 QTLs for pod width, 14 QTLs for pod thickness, 11 QTLs for seed length, 13 QTLs for seed width, 13 QTLs for hundred-pod weight, 10 QTLs for hundred-seed weight. Four QTLs with major effect were detected, including qPWA08.1, qPTA08.3, qPTA08.4, and qSWB08.5, which explained the phenotypic variations of 10.02%–12.15%. Furthermore, 45 stable QTLs were repeatedly detected in more than three environments. QTL clusters were detected on A02, A08, B02, B04, and B08 chromosomes, respectively. In addition, 15 epistatic QTLs were identified that explaining phenotypic variation of 10.23%–51.84%. These results will provide an important theoretical basis for molecular marker-assisted breeding of pod and seed traits in peanut.

Polycomb group (PcG) proteins are pivotal in maintaining gene silencing through epigenetic mechanisms, particularly by catalyzing Histone H3 lysine 27 trimethylation (H3K27me3) via the Polycomb Repressive Complex 2 (PRC2) complex. These modifications are crucial for regulating developmental pathways and environmental stress responses in plants. Despite their importance, the PcG gene family has not been systematically explored in rice (Oryza sativa). In this study, 15 OsPcG genes were identified in the Nipponbare genome, spanning 12 chromosomes and classified into distinct phylogenetic groups. Structural and conserved motif analyses revealed high sequence conservation, while collinearity and Ka/Ks analyses indicated gene family expansion through segmental duplication under purifying selection. Promoter element prediction suggested that many OsPcG genes are responsive to plant hormones and abiotic stress cues. Transcriptome analysis under salt treatment highlighted OsPcG5 as a key salt-responsive gene, with qRT-PCR confirming its dynamic expression. Subcellular localization showed OsPcG5 residing in both the nucleus and plasma membrane, suggesting multifunctional roles. Additionally, overexpression of OsFIE2—a PRC2 component—resulted in elevated H3K27me3 levels and abnormal plant height, linking it to chromatin modification and development. These findings contribute to our understanding of PcG gene functions in rice and offer potential genetic resources for enhancing salt tolerance through epigenetic approaches.