Panicle Characters Research Articles

Evaluation of oat accessions from different ecological groups in the steppe environments of Krasnodar Territory

Background. Studying genetic diversity and identifying sources of valuable agronomic traits for specific environmental conditions is of great importance for plant breeders when they select source material for crop improvement. Materials and methods. Three hundred and seven oat accessions of various ecogeographic origin were tested under the conditions of the Kuban Experiment Station, a branch of the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR), in 2014–2019. Cv. ‘Valdin 765’ served as the reference. Weather conditions across the years of the study were contrasting in terms of the hydrothermal regime. Results. The inter-cultivar and year-to-year variability of the oat collection was analyzed in Krasnodar Territory and accessions promising for breeding were identified for a set of useful agronomic traits. The most significant differences among the studied oat accessions were recorded for the time of ripening and panicle characteristics. High yield of an accession under the conditions of Krasnodar Territory was associated with its high 1000 grain weight, which positively correlated with the duration of the period from panicle emergence to ripening and negatively with the length of the panicle, number of grains per panicle, plant height, and duration of the periods from germination to panicle emergence and from germination to ripening. Conclusion. The study of useful agronomic traits resulted in identifying oat accessions with the yield exceeding the reference (cv. ‘Valdin 765’) by 114–135%, that ripened 6–8 days earlier than the reference, were resistant to lodging, had short stems, manifested combined resistance (9 points) to crown and stem rust, low filminess (< 25%), good leafiness, high oil content (> 6%), increased protein content (> 14%), and high levels of yield structure components.

Evaluating Panicle Architecture and Yield Characteristics in Medium Duration Rice Genotypes through Correlation and Principal Component Analysis

Panicle architecture is a crucial factor that significantly improves economic grain yield. The panicle exhibits considerable variation in its structure, including the number of branches, the length and weight of the panicle, and arrangement of the grains. These traits are not only vital for the plants reproductive efficiency but also for optimizing yield potential. This study focuses on assessing variation in panicle architecture among 31 different medium duration rice genotypes by employing principal component analysis and correlation analysis. This study aimed to dissect the complex relationship between different panicle characteristics. The findings revealed that the first three principal components together explained 60.3% of the total variability. In the first principal component (PC1), the traits SF, PBL, YPH, and HI had the highest positive eigenvalues, indicating their significant impact on overall genotype variations. The second principal component (PC2) was mainly influenced by TSP and SBN, while the third principal component (PC3) was driven by PW and SBL. These results suggest that grain yield is significantly affected by the traits SF, PBL, YPH, HI, TSP, SBN, PW, and SBL. The correlation analysis revealed that the number of secondary branches showed a positive association with unfilled spikelet. Spikelet fertility exhibited a strong positive correlation with yield hectare-1 and harvest index, highlighting its significance in overall yield improvement. Therefore, these components are crucial for differentiating rice genotypes with higher grain yield potential. By evaluating correlation and principal component analysis, we aimed to identify traits that can be targeted for crop improvement initiatives. The findings will contribute to the development of rice varieties that are better suited to specific growing conditions and have enhanced yield potential. This approach will enable the identification of key panicle architecture and yield and yield traits that optimize resource allocation and improve grain filling efficiency, ultimately leading to rice varieties with higher productivity and adaptability.

Application of Open Panicle Traits in Improving the Filling Characteristics at the Base of Indica Rice Panicles.

Panicle-type structure is an important factor affecting rice yield, and an excellent panicle type has become a key indicator in rice breeding. In this study, the indica rice variety R766, which has an open panicle type, was obtained through natural mutation and hybrid selection. Through analyzing differences in panicle structure, panicle yield, and chemical composition between open panicle rice R766 and conventional panicle rice R2928, we found that the angles of the middle and lower branches in R766 were 186.99% and 135.93% greater than those in R2928, respectively. By comparing the grain-filling characteristics of different panicle positions in the two rice varieties, we found that the grain filling at the middle and lower panicle positions of R2928 was significantly lower, accompanied by an increase in the percentage of empty spikelets. However, in R766, the grain-filling rates in the middle and lower panicle positions were consistent with those in the upper panicle position, with significantly higher rates of grain filling and grain plumpness in the middle and lower panicle positions than in R2928. The empty grain rate at the lower panicle position of R766 was 15.25% lower than that of R2928, and the grain filling was 24.75% higher than that of R2928. Additionally, the variation in the 1000-grain weight of grains at different panicle positions in R766 was relatively small, with decreases of 1.55% and 0.38% in the middle and lower panicle positions, respectively, compared with the upper position, whereas R2928 showed decreases of 5.99% and 7.12% in the 1000-grain weight of grains at the middle and lower panicle positions, respectively, compared with the upper position. The cellulose content in the stems of R766 was 7.51% higher than that of R2928, with no significant difference in the cellulose content in the panicle axis and primary branches compared to R2928. The lignin content of the panicle axis in R766 was 8.03% higher than that in R2928, whereas there was no significant difference between the lignin content of the stems and primary branches. This preliminary study revealed the open panicle characteristics of R766 and the reasons for its high basal grain setting rate. This study provides a reference for promoting this open panicle-type indica rice variety to improve yield and disease resistance in environments with high humidity and low sunlight levels.

Karakter Fenotip Malai dan Analisis Fenetik Padi Gogo Lokal Kabupaten Kupang

Panicle is one part of the plant that is very decisive in rice production because it produces grain and rice grains. Each rice variety has its own characteristics including panicle morphological characters. Communities in Kupang Regency are known to still cultivate local upland rice whose panicle character has not been scientifically documented. This study used 5 varieties of local upland rice as a result of exploration from farmers in Kupang Regency which were characterized morphologically by their panicle characters. Characterization data were analyzed using descriptive qualitative and then scored for analysis using Minitab17 software. The results showed that there was a diversity of panicle morphological characters from each local upland rice variety. The differentiating panicle characters of each variety include panicle type, panicle discharge, secondary panicle branches and panicle shaft. The phenetic analysis divided the five local upland rice varieties into two clusters with a similarity index of 79.94%.

Evaluating the Growth and Yield Performances of Selected Rice (<em>Oryza sativa</em> L.) Varieties Grown in Organic Fertilizer

Organic rice cultivation has been receiving a lot of attention in Sri Lanka. Hence, this evaluated the growth and yield performances of 20 rice varieties including four traditional and 16 improved varieties under organic fertilization. The results indicated the significant differences for most of the tested parameters including plant height, flag leaf length and width, root length, tillers and panicle characters and dry weights between rice varieties. The traditional rice variety Madathawalu performed well in terms of plant height, panicle and above ground biomass traits compared to the improved varieties. The highest flag leaf length (42.6cm) was recorded in Madathawalu and the number of leaves per plant was in Bg360 (33.44) followed by Pokkari (28.55). However, tillering characteristics were superior in improved varieties (Bg360, Ld365 and Bg357). The highest root length was obtained in Sulai (15.87cm), while the lowest was in Bg372 (9.53cm). Bg369 had the highest 100 grain weight (3.29g) followed by Pokkari (2.95g), Suduheenaty (2.95g) and Bg 94-1 (2.9g), while the lowest was recorded in Ld365 (1.58g). Overall, the highest total panicle dry weight was observed in Madathawalu (24.29g) followed by Aeron 9-3 (22.7g) and Bg360 (20.16g) suggesting that these three rice varieties can be cultivated with the application of organic fertilize

Optimizing the Working Parameters of Pneumatic Pollinators Based on the Kinematic Properties of Rice Panicles

Highlights An experimental platform for the kinematic characteristics of panicles was constructed. A regression model for the kinematic characteristics of panicles and working parameters was established. The multi-objective optimization based on the kinematic characteristics of rice panicles was carried out. The optimized combination of working parameters was verified by field pollination experiments. Abstract. Pollen shedding and dispersal processes are inextricably linked to the movement state of hybrid rice panicles. The purpose of this work was to study the effect of the working parameters of the pneumatic pollinator on the kinematic characteristics of hybrid rice panicles during flowering and to further optimize the working parameters of the pollinator. An experimental platform was built to characterize the movement of the panicle. Orthogonal experiments were conducted with airflow velocity, action position, and walking speed as experimental factors and kinematic parameters such as displacement, velocity, and acceleration of the rice panicle as experimental indicators. A quadratic regression model between the working parameters and the motion characteristics of the rice panicle was constructed and analyzed by analysis of variance (ANOVA). Matrix analysis was used for multi-objective optimization of the working parameter combinations. Field pollination trials were conducted for the optimized combination of parameters. The results showed that the coefficients of determination of the regression models were all above 0.85, which indicated good accuracy. The motion characteristics of the panicle, including the displacement maximum, velocity maximum, and acceleration maximum, can be maintained at a high level when the airflow velocity is 24 m/s, the action position is 120 mm from the top of the panicle, and the walking speed is 0.4 m/s. The field experiments showed that the optimization results could obtain the desired pollen density, distribution, and uniformity. This study can serve as a reference for the development of pneumatic hybrid rice pollination theory and the optimal design of the pollinator structure. Keywords: Hybrid rice seed production, Kinematic characteristics, Mechanized pollination, Multi-objective optimization.

Foliar cytokinins or brassinosteroids applications influence the rice plant acclimatization to combined heat stress.

The effect of different foliar sprays numbers of cytokinins - (CK) and brassinosteroids - (BR) on the physiological, biochemical, and panicle parameters of rice plants subjected to combined heat stress (high day/night temperatures) were studied in three different experiments. The treatments established for the first (E1) and second (E2) experiments were the following: i) absolute control, ii) stress control, iii) heat stress + one foliar spray of CK, iv) heat stress + two foliar sprays of CK, v) heat stress + three foliar sprays of CK, vi) heat stress + one foliar spray of BR, vii) heat stress + two foliar sprays of BR, or viii) heat stress + three foliar sprays of BR. For the third experiment (E3), the treatments were the following: i) absolute control, ii) stress control, iii) heat stress + three foliar applications of CK, iv) heat stress + three foliar applications of BR. Rice-stressed plants and sprayed with three foliar sprays of CK or BR had a better stomatal conductance in E1 and E2 compared to their heat-stressed control. The relative tolerance index suggests that three CK or BR applications helped to mitigate the combined heat stress in both experiments. The foliar CK or BR applications at the flowering and grain-filling stages in rice-stressed plants increased Fv/Fm ratio and panicle characteristics (number of filled spikelets and the percentage of panicle blanking in E3). In conclusion, foliar applications of BR or CK can be considered an agronomic strategy to help improve the negative effect of combined heat stress conditions on the physiological behavior of rice plants during different phenological stages.

CgSSR marker-based genome-wide association study identified genomic regions for panicle characters and yield in rice (Oryza sativa L.).

To improve production efficiency, positive alleles corresponding to yield-related attributes must be accumulated in a single elite background. We designed and used cgSSR markers, which are superior to random SSR markers in genome-wide association study, to identify genomic regions that contribute to panicle characters and grain yield in this study. As evidenced by the high polymorphic information content value and gene diversity coefficient, the new cgSSR markers were determined to be highly informative. These cgSSR markers were employed to generate genotype data for an association panel evaluated for four panicle characters and grain yield over three seasons. For five traits, 17 significant marker-trait associations on six chromosomes were discovered. The percentage of phenotypic variance that could be explained ranged from 4% to 13%. Unrelated gene-derived markers had a strong association with target traits as well. Trait-associated cgSSR markers derived from corresponding or related genes ensure their utility in direct allele selection, while other linked markers aid in allele selection indirectly by altering the phenotype of interest. Through a marker-assisted breeding approach, these marker-trait associations can be leveraged to accumulate favourable alleles for yield enhancement in rice. © 2022 Society of Chemical Industry.

Dry matter production and panicle characteristics of high yield and good taste indica hybrid rice varieties

Indica hybrid rice (Oryza sativa) production aims to achieve two crucial targets: high yield and good taste. This study selected three types of indica hybrid rice according to grain yield and taste value, including high yield and good taste (HYGT), low yield and good taste (LYGT), and high yield and poor taste (HYPT), to analyze yield components, corresponding growth characteristics, and rice taste quality. When values were averaged across varieties and years, there were almost no differences in taste value between HYGT and LYGT; HYGT showed a significant increase in yield, owing to a higher number of panicles and spikelets per panicle, with a respective increment of 16.2 and 20.6%. The higher grain yield of HYGT compared with LYGT was attributed to three key factors: a higher leaf area index (LAI) during heading, a higher ratio of grain to leaf, and a higher biomass accumulation at maturity. HYGT and HYPT achieved similar high yields; however, HYGT had more panicle numbers and lower grain weight. In addition, HYGT showed a significantly higher taste value than HYPT, attributed to its significantly lower protein and amylose contents, with reductions of 8.8 and 15.7%, respectively. Lower protein and amylose contents might be caused by a proper matter translocation from vegetative organs to panicle. This study suggested that reasonable panicle characteristics and translocation efficiency from vegetative organs to panicle during heading to maturity are the key factors in balancing yield and rice taste quality. These results will provide valuable insights for rice breeders to improve the grain yield and quality of indica hybrid rice.

Fertilizer Effects on Panicle Characteristics, Grain Weight and Yield of Upland Rice in Lowlands of Taita Taveta, Kenya

This study was done at Mlughi Agricultural demonstration farm in Bura, Taita Taveta County-Kenya to test upland rice varietal performance and di-ammonium fertilizer effects on panicle characteristics and yield parameter. A randomized complete block design (RCBD) was used with seven upland rice varieties and three fertilizer levels. The treatments were replicated thrice to give a total of 63 treatment combinations or plots. The experiment was carried out for two seasons (short rains from October to December 2018 and long rains from March to May 2019). The upland rice varieties included 17KH09010014B, 17KH09010093B, AT 058, China Hybrid, NERICA 1, NERICA 4, and NERICA 10. The fertilizer treatments were di-ammonium phosphate fertilizer (DAP), farm yard manure (FYM), and a control of no fertilizer. Topdressing was done at the flowering stage with NPK fertilizer. Data collected included plant height, number of leaves, tiller number, panicle length, spikelets count per panicle, grain yield ha-1 and weight of 1000 grains. The data were subjected to multivariate analysis of variance (MANOVA) using R version 3.6.1 program and Tukey’s HSD test, p ≤ 0.05 was used to separate the significant means. The results showed that there was significant influence (p = 0.0001) of overall seasonal, treatment and variety on the yield of rice grains in tonnes per hectare. The 2018 season had the lowest tonnage compared to the 2019 season. Crops under the control treatment yielded the least tonnage per hectare while the DAP treated fields yielded the highest in both seasons. NERICA 4 was the highest yielding variety while AT 058 was the least yielding among the treatments in both seasons. It was therefore concluded that the application of DAP and FYM significantly increased rice productivity. Farmers are therefore encouraged to carry out soil fertility testing occasionally and to plant NERICA varieties.

Characteristics of panicle stem growth and flowering period of the parents of hybrid rice in machine-transplanted seed production

<p id="C3">To study the characteristics of panicle and stem growth and flowering period of restorer line and sterile line under mechanized transplanting mode, and to analyze the reasons for the difficulty of parental flowering period meeting under mechanized transplanting mode Chenghui 727×Shu 21A and Yahui 2115×Yixiang 1A were selected as the materials, and the field experiment was carried out from 2019 to 2020 in this study. Two transplanting methods and seedling ages were determined. Leaf age dynamics, panicle stem growth dynamics, and heading dynamics of restorer line and sterile line were investigated, and the effects of different treatments on the growth and development of panicle, stem and leaf, and flower state of the restorer line and sterile line were statistically analyzed. The results were as follows: (1) The total number of leaves in mechanical transplanting parents decreased by 0.3-0.8 leaves in restorer lines while the sterile line added 0.1-0.4 leaves. Meanwhile, the total number of leaves in restorer lines decreased with the decrease of seedling age, while there was no significant change in the total number of leaves of male sterile lines. (2) The growth process of panicles, stems and leaves of restorer lines in mechanical transplanting was delayed by 2-5 days, while that of sterile lines was delayed by 5-10 days. The panicle differentiation of restorer lines began after jointing, while the panicle differentiation of sterile lines began 5-10 days after jointing. The panicle differentiation duration of restorer lines and sterile lines did not change significantly. The young ear growth curves of all treated parents were well fitted with Logistic curves (<italic>R</italic>²&gt;0.99). (3) The duration from seeding to heading of machine transplanting parents was longer than that of artificial transplanting parents. The effect of lengthening seedling age was the same as the change of transplanting method and the response of sterile lines to transplanting method and seedling age was more significant than that of restorer lines. (4) The flower encounter index of long seedling age under artificial transplanting in each combination was 100%, and the flower encounter was the best. Flowering encountering index was between 40%-60% of long seedling age under mechanical transplanting and short seedling age under artificial transplanting, followed by flowering status. However, the flowering index of the short seedling age combination of Chenghui 727 × Shu 21A and Yahui 2115 × Yixiang 1A was 0 and 18.18% under mechanical transplanting, respectively, indicating that the absent of flowering date seriously. In conclusion, the growth and development of ear, stem, and leaf of parents were delayed under mechanized transplanting mode, and the prolonged seedling age aggravated the growth and development lag phenomenon of parents. There were some differences in the growth, development, and flowering characteristics between restorer lines and sterile lines under different transplanting methods and seedling ages. The difference in the response of restorer lines and sterile lines to cultivation measures was the main reason for the absence of flowering dates of parents.

Omics: a tool for resilient rice genetic improvement strategies.

Rice is pivotal pyramid of about half of the world population. Bearing small genome size and worldwide utmost food crop rice has been known as ideal cereal crop for genome research. Currently, decreasing water table and soil fatigue are big challenges and intense consequences in changing climate. Whole sequenced genome of rice sized 389Mb of which 95% is covered with excellent mapping order. Sequenced rice genome helps in molecular biology and transcriptomics of cereals as it provides whole genome sequence of indica and japonica sub species. Through rice genome sequencing and functional genomics, QTLs or genes, genetic variability and halophyte blocks for agronomic characters were identified which have proved much more useful in molecular breeding and direct selection. There are different numbers of genes or QTLs identified for yield related traits i.e., 6 QTLs/genes for plant architecture, 6 for panicle characteristics, 4 for grain number, 1 gene/QTL for tiller, HGW, grain filling and shattering. QTLS/genes for grain quality, biotic stresses and for abiotic stresses are 7, 23 and 13 respectively. Low yield, inferior quality and susceptibility to biotic and abiotic stresses of a crop is due to narrow genetic background of new evolving rice verities. Wild rice provides genetic resources for improvement of these characters, molecular and genomics tool at different stages can overcome these stresses and improve yield and quality of rice crop.

Expected genetic progress of F2 resulted from crossovers of paddy Situ Patenggang variety with IPB 3S variety

This study aims to determine the expected genetic progress of the F2 population resulting from the crossing of Situ Patenggang variety with IPB 3S variety, which was carried out in the experimental garden of the Faculty of Agriculture, University of Mataram, Nyur Lembang Village, Narmada District, West Lombok Regency in July to December 2018. The material used in this study is Situ Patenggang varieties, IPB 3S varieties, Inpari 32 varieties, F1 resulting from the crossing of Situ Patenggang varieties with IPB 3S varieties and F2 selfing from F1. Using Augmented design with RAK models. Analysis of Hope Genetic Progress (KGH) allegedly using the formula Knight (1979). The results showed that the high expected genetic progress value was found in the characters of productive tillers, number of nonproductive tillers, number of seeds containing panicle, number of empty seedlings, and weight characteristics of 1000 seeds, while genetic progress was quite high in the length of panicle characters.

Panicle branching behaviour of rice Inpari IR Nutri Zinc

As a staple food, rice can be used as a bio fortification. For this necessity, Indonesian Agency for Agriculture Research and Development (IAARD) developed rice variety which was rich of Zn content to overcome child stunting. To understand the panicle branching behavior of Inpari IR Nutri Zinc, we collected panicle branching data from different sites and agronomical practices. Data were collected from three locations in West Java, i.e Cianjur, Majalengka, and Ciamis during May until October 2020. Among sites showed a significant differences of panicle branching. The best performance of Inpari IR Nutri Zinc panicle branching was showed at Majalengka rather than Ciamis and Cianjur. It was predicted because of temperature differences, as Cianjur’s was higher than those Majalengka’s and Ciamis’. Based on planting space, L5 was better than that L2 in number of grains per panicle, number of primary branches, number of secondary branches, total length of primary branches, and number of filled-grain per panicle characters. Meanwhile, L2 in Majalengka and Ciamis showed higher value in three panicle branching characters. Further, the L2 in Majalengka showed higher value and significantly difference than that in Ciamis in seven panicles branching characters bio pesticide application also affected some panicle branching characters significantly.

Genetic improvement of panicle-erectness japonica rice toward both yield and eating and cooking quality

The panicle erectness (PE) japonica cultivars have been widely planted in China. However, the relatively low yield level per plant and inferior eating and cooking quality of PE japonica cultivars are needed to improve further. In present study, a typical PE japonica cultivar, Nanjing 46, was selected as target for improving yield and grain quality by the way of introgression of Gn1a, qPC-1, and sd1 allele conferring grain number, grain protein content (GPC), and plant height, respectively. We obtained the improved lines containing Gn1a, qPC-1-sd1, and qPC-1-sd1-Gn1a through consecutive backcrossing with the help of gene-tagged markers. Agronomic and quality trait analysis showed that the introgression of Gn1a allele exhibited a positive effect on many panicle characters, including longer panicle length and grain length, more grain numbers per panicle, finally resulting in an increased grain yield. The introgression of sd1 allele could significantly reduce the plant height, and no negative effects were found on the panicle performance of the plants containing Gn1a allele. The introgression of qPC-1 could significantly reduce GPC, then increase rice palatability based on the RVA analysis. The result indicated that it is feasible to improve rice yield and grain quality of PE japonica cultivars by replacing these three favorable alleles simultaneously. This strategy could also be applied in the improvement of common japonica cultivars.

Genetic diversity of panicle morphological traits of rice (Oryza sativa L.)

The variability of rice genotypes is a source of germplasm for rice breeding. As one of the major organs related to yield components in rice, panicle architecture is an important part to be studied, while the information is still limited. The study aimed to obtain information on the diversity of rice genotypes on the panicle character and investigate their relationship within the panicle characters. The experiment was conducted during two seasons using 100 rice genotypes. The analysis of variance showed that genotypes and seasons are significantly different. The character of length of first grain from first node and the number of primary branches increased during the rainy season (rainy season 2015/2016). The performance of panicle traits had been influenced by environment factors regarding to quantitative traits which encoded by multiple genes.

Characteristic of panicle in M4 red rice mutants

The need for rice is always increasing every year in line with population growth making rice commodities have a very important role. Red rice which has been known for a long time, needs to be given priority in research to overcome the problem of food and nutrition shortages. Rice panicle, a crucial organ that has economic values, is an important yield component to improve. This study aimed to obtain information on relationship within the panicle characters on rice production. The experiment was conducted within 6 month using 10 red rice mutant lines M4 and 2 non-mutant lines as controls. Data from yield components used were number of grains per panicle, panicle density, percentage of filled grain per panicle, grain length, grain width, and grain thick. Based on the results of the path analysis on these characters, it is known that four characters that have a total positive and significant direct effect on the weight of grain per panicle were the number of grains per panicle, panicle density, panicle length and percentage of filled grain per panicle. Hence, these characters are important and effective to be used as a selection component in increasing grain production in red rice plants. Tests of several M4 generation red rice mutants based on grain characterization show very significant differences in grain length and grain width characters. The longest grain is GK2 strain (10.33 mm) and the widest grain is G9 strain (3.29 mm).

Performance and utilization of local sorghum (Sorghum bicolor L.) in West Nusa Tenggara

Sorghum was seen as one of the crops best suited to future climate change due to its ability to adapt to conditions. such as drought, salinity and high temperatures. This study was aim to know the performance and utilization of local sorghum in West Nusa Tenggara especially in Bima District. A collection of sorghum samples was performed on a population of sorghum farmers in both small and larger planting areas. Observations were made on the characteristics of plant and panicle. In addition, interviews were conducted on farmers using questionnaires to obtain data on harvested area, planting location, harvest time, and sorghum utilization. Qualitative data obtained were analyzed descriptively and presented in tables and figures, while quantitative data were analyzed using Annova test continued by BNJ/Tukey at 0.05 level of significant. There are six (6) local sorghum varieties whose appearance are very different from one another namely gando bura, gando keta, gando keta 2, latu kala, latu keta, and latu keta 2. Varieties had effect on plant height, diameter of stem, leaf size and panicle length. Apart from being distinguished by the color of the husk, they are also distinguished from the shape and presence of fur at the tip seed. Specifically gando bura variety has the ability producing until 12 tillers. Sorghum has been consumed by Bima community as a main food mixed with rice, as well as processed food such as dodol sorghum and sorghum porridge.

Transcriptome Profiling Analysis Reveals Co-regulation of Hormone Pathways in Foxtail Millet during Sclerospora graminicola Infection.

Sclerospora graminicola (Sacc.) Schroeter is a biotrophic pathogen of foxtail millet (Setaria italica) and increasingly impacts crop production. We explored the main factors for symptoms such as dwarfing of diseased plants and the “hedgehog panicle” by determining panicle characteristics of varieties infected with S. graminicola and analyzing the endogenous hormone-related genes in leaves of Jingu 21. Results indicated that different varieties infected by S. graminicola exhibited various symptoms. Transcriptome analysis revealed that the ent-copalyl diphosphate synthetase (CPS) encoded by Seita.2G144900 and ent-kaurene synthase (KS) encoded by Seita.2G144400 were up-regulated 4.7-fold and 2.8-fold, respectively. Results showed that the biosynthesis of gibberellin might be increased, but the gibberellin signal transduction pathway might be blocked. The abscisic acid (ABA) 8′-hydroxylase encoded by Seita.6G181300 was continuously up-regulated by 4.2-fold, 2.7-fold, 14.3-fold, and 12.9-fold from TG1 to TG4 stage, respectively. Seita.2G144900 and Seita.2G144400 increased 79-fold and 51-fold, respectively, at the panicle development stage, promoting the formation of a “hedgehog panicle”. Jasmonic acid-related synthesis enzymes LOX2s, AOS, and AOC were up-regulated at the early stage of infection, indicating that jasmonic acid played an essential role in early response to S. graminicola infection. The expression of YUC-related genes of the auxin synthesis was lower than that of the control at TG3 and TG4 stages, but the amidase encoded by Seita.2G313400 was up-regulated by more than 30-fold, indicating that the main biosynthesis pathway of auxin had changed. The results suggest that there was co-regulation of the hormone pathways during the infection of foxtail millet by S. graminicola.

So Close Yet So Different: Cultural Differences Among Farmers in Central Kenya Affect Their Knowledge of Sorghum (Sorghum bicolor [L.] Moench) Landrace Identification

So Close Yet So Different: Cultural Differences among Farmers in Central Kenya Affect Their Knowledge of Sorghum (Sorghum bicolor [L.] Moench) Landrace Identification. Whether knowledge of landrace identification is shared among farmers in rural societies is a matter of debate in crop diversity research, and the influence of culture on knowledge heterogeneity remains largely misunderstood. This study analyzes the heterogeneity of farmers’ knowledge of crop landrace identification, and investigates factors involved in its patterns. It especially explores the effect of cultural differences by comparing how three ethnolinguistic groups identify and name sorghum diversity in the Mount Kenya region. A set of 293 panicles representing sorghum diversity in the study area was presented for identification to 96 farmers randomly selected in the three groups. A subset of 287 panicles was scored for morphological characteristics using 16 qualitative descriptors, and neutral genetic diversity of 170 of them was described using 18 SSR genetic markers. Distance-based analyses were applied to analyze knowledge patterns within and between groups and to describe the structure of sorghum morphological and genetic diversity. Results show that the degree of heterogeneity of knowledge among farmers varies strongly according to both their ethnolinguistic membership and panicle characteristics, despite their high geographic proximity. The effect of farmers’ experience of landraces and of pathways for social learning on inter-individual variations of knowledge is discussed.