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The cytochrome P450 (CYP450) gene family plays a critical role in plant growth and developmental processes, nutrition, and detoxification of xenobiotics in plants. In the present research, a comprehensive set of 105 OsCYP71 family genes was pinpointed within the genome of indica rice. These genes were categorized into twelve distinct subfamilies, where members within the same subgroup exhibited comparable gene structures and conserved motifs. In addition, 105 OsCYP71 genes were distributed across 11 chromosomes, and 36 pairs of OsCYP71 involved in gene duplication events. Within the promoter region of OsCYP71, there exists an extensive array of cis-elements that are associated with light responsiveness, hormonal regulation, and stress-related signaling. Further, transcriptome profiling revealed that a majority of the genes exhibited responsiveness to hormones and were activated across diverse tissues and developmental stages in rice. The OsCYP71P6 gene is involved in insect resistance, senescence, and yield-related traits in rice. Hence, understanding the association between OsCYP71P6 genetic variants and yield-related traits in rice varieties could provide novel insights for rice improvement. Through the utilization of linear regression models, a total of eight promoters were identified, and a specific gene variant (Ser33Leu) within OsCYP71P6 was found to be linked to spikelet fertility. Additionally, different alleles of the OsCYP71P6 gene identified through in/dels polymorphism in 131 rice varieties were validated for their allelic effects on yield-related traits. Furthermore, the single-plant yield, spikelet number, panicle length, panicle weight, and unfilled grain per panicle for the OsCYP71P6-1 promoter insertion variant were found to contribute 20.19%, 13.65%, 5.637%, 8.79%, and 36.86% more than the deletion variant, respectively. These findings establish a robust groundwork for delving deeper into the functions of OsCYP71-family genes across a range of biological processes. Moreover, these findings provide evidence that allelic variation in the promoter and amino acid substitution of Ser33Leu in the OsCYP71P6 gene could potentially impact traits related to rice yield. Therefore, the identified promoter variants in the OsCYP71P6 gene could be harnessed to amplify rice yields.
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Assessing genetic diversity and development of a core set of elite breeding lines is a prerequisite for selective hybridization programes intended to improve the yield potential in rice. In the present study, the genetic diversity of newly developed elite lines derived from indicax tropical japonica and indicax indica crosses were estimated by 38 reported molecular markers. The markers used in the study consist of 24 gene-based and 14 random markers related to grain yield-related QTLs distributed across the rice genome. Genotypic characterization was carried out to determine the genetic similarities between the elite lines. In total, 75 alleles were found using 38 polymorphic markers, with polymorphism information content ranging from 0.10 to 0.51 with an average of 0.35. The genotypes were divided into three groups based on cluster analysis, structure analysis and also dispersed throughout the quadrangle of PCA, but nitrogen responsive lines clustered in one quadrangle. Seven markers (GS3_RGS1, GS3_RGS2, GS5_Indel1, Ghd 7_05SNP, RM 12289, RM 23065 and RM 25457) exhibited PIC values ≥ 0.50 indicating that they were effective in detecting genetic relationships among elite rice. Additionally, a core set of 11 elite lines was made from 96 lines in order to downsize the diversity of the original population into a small set for parental selection. In general, the genetic information collected in this work will aid in the study of grain yield traits at molecular level for other sets of rice genotypes and for selecting diverse elite lines to develop a strong crossing programme in rice. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01190-8.
RESUMO
[This corrects the article DOI: 10.1371/journal.pone.0176236.].
RESUMO
Echinochloa colona (L.) Link is a very problematic weed in up land and medium land rice causing significant reduction in yield. In the present investigation, laboratory and field experiments were conducted to evaluate the nature of interaction E. colona on germination and growth of the up land rice cultivar 'Vandana'. The effects of decomposing and decomposed aqueous leachates (1-10% w/v) obtained from the dried biomass of 20, 30, 40 and 60 days old Ecolona plants were studied on rice using petridish bioassay technique with three different types of culture media like filter paper, soil, and soil + activated charcoal. The decomposing leachates of E. colona showed strong toxic effect on root and shoot growth of rice, the highest being noted with 10% leachates of 60 days old plant residue. It inhibited root and shoot growth by 100% and 43.9% respectively as compared to control. The corresponding decomposed leachates inhibited rice germination by 90% and root and shoot growth by 70 and 25% respectively. These toxic effects of leachates showed in filter paper medium were significantly reduced in soil and soil plus activated charcoal media proving their allelopathic nature. In a field experiment, E. colona and rice were grown in proportions of 1:1, 1: 2 and 1:4, the total plant density being maintained at 100 pants m(-2). The height and dry matter of rice were adversely affected with increasing in E. colona population. From another similar field trial, data on dry matter of 20, 30, 40, and 60 days old plants were taken and their plant relative yield (PRY) and relative yield total (RYT) values were calculated. The PRY and RYT values were found to be less than unit (< 1) throughout the growth period studied which suggested the presence of severe antagonistic interspecific interaction between rice and E. colona due to allelopathy.
