Narrow Leaf Research Articles

Assessing lead and cadmium tolerance of Chenopodium ambrosioides during micropropagation: an in-depth qualitative and quantitative analysis.

The tolerance of Chenopodium ambrosioides to some heavy metals under in vitro environment was thoroughly investigated. A micropropagation protocol was developed to facilitate the mass production of plants and to identify metals-tolerant species for potential use in the restoration of polluted areas. Nodal explants exhibited callus formation when treated with N6-benzyladenin (BA) (1.5 mg/l) and a combination of BA/α-naphthalene acetic acid (NAA) at concentrations of 1.5/1.0 mg/l on the Murashige and Skoog (MS) medium. The optimal shoot formation was achieved with the callus grown on a medium enriched with 1.5/1.0 mg/l BA/NAA, resulting in an impressive number (21.89) and length (11.79 cm) of shoots. The in vitro shoots were rooted using NAA (1.0 and 1.5 mg/l) and were acclimatized in pots with 71% survival rate. After standardizing micropropagation protocol, the in vitro shoots were subjected to various doses of lead nitrate (Pb(NO3)2 and cadmium chloride (CdCl2). Pb(NO3)2 and CdCl2 in the media let to a reduction in shoot multiplication, decreasing from 18.73 in the control group to 11.31 for Pb(NO3)2 and 13.89 for CdCl2 containing medium. However, Pb(NO3)2 and CdCl2 promoted shoot length from 5.61 in the control to 9.86 on Pb(NO3)2 and 12.51 on CdCl2 containing medium. In the case of Pb(NO3)2 treated shoots, the growth tolerance index (GTI) ranged from117.64% to 194.11%, whereas for CdCl2 treated shoots, the GTI ranged from 188.23% to 264.70%. Shoots treated with high level of Pb(NO3)2induced reddish-purple shoots, while a low level of Pb(NO3)2 induced shoots displayed both green and reddish-purple colors in the same explants. In CdCl2 treated culture, the toxic effects were narrow leaf lamina, elongated petiole and a dark reddish purple coloration. These findings highlight the remarkable potential of C. ambrosioides to maintain growth and organogenesis even in the presence Pb(NO3)2 and CdCl2 on the MS medium, indicating a high degree of metal tolerance.

Comparative efficacy of different broad-spectrumweedicides on wheat crop and their impact on yield

Wheat Triticum aestivum L. is cereal and the predominant food crop in Pakistan, cultivated on an area of greater than one million hectares. A number of factors, including weeds, have affected yield in this crop. The weeds are competing with wheat plants for moisture, space, nutrients, light and a number of other growth factors which contribute to low yield and are determental to the quality of produce. A yield loss of 10 to 60% can be attributed to weeds. In fact, the only acceptable method of weed control will be the use of herbicides, due to rising labour and power costs. An experiment was laid out under irrigation system in Tehsil Samundri, to determine the broad and narrow leaf weed population in different area in wheat crop field and efficacy of five different broad spectrum weedicides during Rabi crop season. The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications, with plot size of 200x 180 m2. Five different herbicides were applied as Atlantis 3.6 % WG @100 gm/ Acre, Isoproturan 50 % WP @ 800gm / Acre, Affinity 50 WP @ 800 gm/Acre, Proturon 50 % WP @ 800 gm/Acre and Pallas 45OD @ 160ml/Acre with control treatment. An average of 50.63/ m2 of weed population was observed. All weedicides significantly decreased weed population over control and maximum grain yield (40.55mon acre-1) was obtained where Affinity was applied @ 800 gm/acre. It was however statistically at par with the grain yield of 38.40mon acre-1 where Atlantis was applied @ 160 gm/ Ac. The control was obtained from all the herbalicidal applications. Therefore, in order to control broad and narrow leaf weeds and increase the yield of wheat it is recommended that Affinity and Atlantis be applied 800 and 160gm @acres respectively

Analysis the Use of Gempur 480 SL Chemicals on the Mortality of Weed Types

This study aims to determine the types of weeds that can be controlled or destroyed using the chemical Gempur 480 SL at PT. Toba Pulp Lestari Estate Tele. The method used in this research is a field survey method at 3 different masl by means of purposive sampling. Based on the research that has been done, it shows that the treatment of weed types found in Estate Tele is dominated by sedge weeds such as Cyperus rotundus and broad leaf weeds such as Boreria latifolia, Climedia hirta and Melastoma malabathtricum, while narrow leaf weeds such as Petridium (elephant fern), Stenochlaena (Vegetable ferns), Dicranopteris linearis (Wire ferns) are relatively few compared to sedge weeds and broadleaf weeds. The use of the concentration of the hebicide Gempur 480 SL of 1.25% can suppress weed growth where the percentage of dead weeds is higher. Weeding rounds have a significant effect on the percentage of weeds that die and the percentage of weeds that don't die. The highest percentage of weeds that died was in Weeding Round 3 (WR3). The interaction of herbicide concentrations and weeding rounds had a significant effect on the percentage of live weeds and the percentage of weeds that were not alive. The increase in the percentage of dead weeds will increase with the increasing concentration of the herbicide Gempur 480 SL, especially if the increased concentration of the herbicide Gempur is combined with Weeding Round 2 (WR2).

The trait co-variation regulates the response of bryophytes to nitrogen deposition: A meta-analysis

The nitrogen deposition has the potential to alter the trait composition of plant communities by affecting the fitness and physiological adaptation of species, consequently exerting an influence on ecosystem processes. Despite the importance of bryophytes in nutrient and carbon dynamics across different ecosystems, there is a lack of research examining the relationship between nitrogen deposition and the co-variation of bryophyte traits. To address this gap, a meta-analysis was conducted using data from 27 independent studies to investigate potential associations between trait co-variation of bryophytes and nitrogen deposition. The results revealed that interspecific variability regulates the influence of nitrogen deposition on bryophytes by affecting trait co-variation. Multiple correspondence analysis identified six combinations of closely related traits. For example, species with unbranched main stems frequently exhibit robust leaf midribs, leading to leaf wrinkling and leaf clasping around the stem as a response to water loss. Some weft or mat species tend to obtain resources (nitrogen) through their scale hairs on the main stem. Some species with narrow leaves require leaf teeth to maintain a normal leaf shape. The subgroup analyses indicated that certain traits, including unbranched main stem, changes in leaf morphology, robust leaf midrib, main stem without scale hairs, narrow leaf, leaf margin with teeth, undeveloped apophysis, and erect capsule minimize interaction with pollutants and represent a resource strategy. Conversely, functional traits representing a resource acquisition strategy, such as branched main stem, no changes in leaf morphology, short and weak leaf midrib, main stem with scale hairs, broad leaf, leaf margin without teeth, developed apophysis, and non-erect capsule increase pollutant exposure. Overall, our results suggest that anthropogenic global change may significantly impact bryophytes due to changes in their individual physiology and colony ecological indicators caused by increased nitrogen deposition.

Do mutations modifying the leaf area (nr3) and the number of potential seeds (dfc) influence photosynthetic gas exchange characteristics in common buckwheat Fagopyrum esculentum Moench?

Contemporary buckwheat breeding in Russia is based mainly on a Mendelian mutation det. Some additional mutations are being considered for inclusion in buckwheat breeding programs. Among them are the nr3 (narrow leaf 3) and dfc (determinate floret cluster). We evaluated the effects of the mutations on both the characteristics of photosynthetic gas exchange and the number of seeds per plant. The nr3 reduces the leaf surface area by 1.4 times. The mutant plants show some compensatory increase in photosynthesis rate, which, however, is not enough to reach the level of the source ability as in the wild type since the number of seeds per plant is significantly decreased. The possibility of using this mutation in buckwheat breeding depends on the accumulation of modifiers that increase either leaf size or photosynthesis rate. The reduced number of flowers of the dfs mutation is compensated by an increase in flower fertility, and the number of seeds per plant does not change compared to the wild type. It explains the absence of differences between the dfs and wild type in terms of the photosynthesis rate. This experiment did not reveal any problems for using the dfc mutation in breeding. In general, the results of the work support the photosynthesis rate in buckwheat is regulated based on the source-sink ratio.

A High-Quality Genome Assembly for Cercospora janseana, Causal Agent of Narrow Brown Leaf Spot of Rice.

Cercospora janseana causes narrow brown leaf spot of rice. A nearly complete telomere-to-telomere reference genome was assembled with a combination of Oxford Nanopore and Illumina sequences. The genome assembly has a total length of 39,075,509 bp and consists of 15 chromosomes, 14 of which have telomeric repeats at both ends. The assembly N50 is 2.97 Mb and the L50 is five contigs. RNA-seq-mediated gene annotation identified 10,850 genes, including 955 predicted secreted proteins and 361 predicted effector proteins. This highly contiguous and almost complete C. janseana reference genome will be a vital resource for further investigation of host-pathogen interactions and genome evolution within this pathosystem. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Characterization of traditional small potato (Solanum tuberosum L.) cultivars for nutritional, quality traits and ploidy level

Traditional small potato cultivars of North Eastern region of India are an important food source, but no documentation is availableregarding their ploidy level and nutritional worth. The study was undertaken to explore these cultivars to determine their ploidy levelby flow cytometry method. Fluorescence-activated cell sorter (FACS) based method was used for the analysis of ploidy level and theknown diploid potato clone Solanum chacoense was used as the reference clone. The ploidy level of these cultivars was determined bycomparing the value of mean peak position of G1 of reference diploid clone with mean peak position of G1 of small potato cultivars.Results indicated that all the 11 small potato cultivars collected from the Northeastern region were tetraploid with an average genomesize of 837.38 Mb although they were suspected to be diploid based on the tuber characters and overall plant morphology. Thesecultivars were characterized by having anthocyanin pigmentation of newly emerged sprouts and eye on tuber, small and narrow leaf,long stolon length (average 7.38 cm) and high number (average 33.90/plant) of very small (average 7.41 g) tubers compared to thecommercial potato varieties. However, these cultivars surpassed India’s commercial tetraploid potato varieties for dry matter, starch,ascorbic acid, β-carotene and total phenol contents. Appreciably rich nutritional profile coupled with matching levels of ploidy not onlyenhanced the biodiversity of cultivated potato but also suggested the possibility of utilizing these cultivars in the breeding programmeto enhance nutrient and antioxidant contents.

Genetic analysis for green fodder quality characters in concurrence of heterosis and genotype-by-trait biplot in bread wheat (Triticum aestivum L.)

Animal health is of utmost importance, whereas green fodder supply is limiting day-by-day. In the present investigation, eight diversewheat varieties were crossed in half-diallel fashion and were analysed along with 28 F1s for green fodder digestibility and crude protein in the Bundelkhand region of Madhya Pradesh and Uttar Pradesh. The parental genotype NIAW34 showed the highest organic matter (91.65%), followed by PBW723 (91.47%) and GW322 (91.30%). Acid detergent fiber (ADF), cellulose and lignin contents ranged from 26.86-33.89%, 2.59–28.02% and 2.91–4.40%, respectively for parents and hybrids. Hemicellulose content varied from 27.60–36.58% and the parents namely, HI1544 (30.52%) and GW322 (29.91%) were found promising with the hybrids viz., HD3086/DBW110, HI1544/NIAW34 and GW322/NW5054. The study revealed that wheat green fodder quality was comparable with the sorghum and maize crops.Organic matter and neutral detergent fiber revealed a preponderance of additive gene action, whereas protein and nitrogen contents,cellulose, lignin, acid detergent fiber and hemicellulose showed an average degree of dominance more than unity. The narrow leaf wheat genotype DBW110 exhibited higher cellulose and lignin contents, providing insight for on-field selection. The per se performance and genotype by trait biplot revealed the potential of wheat variety, GW322 for multiple fodder digestibility traits.

NLG1, encoding a mitochondrial membrane protein, controls leaf and grain development in rice

BackgroundMitochondrion is the key respiratory organ and participate in multiple anabolism and catabolism pathways in eukaryote. However, the underlying mechanism of how mitochondrial membrane proteins regulate leaf and grain development remains to be further elucidated.ResultsHere, a mitochondria-defective mutant narrow leaf and slender grain 1 (nlg1) was identified from an EMS-treated mutant population, which exhibits narrow leaves and slender grains. Moreover, nlg1 also presents abnormal mitochondria structure and was sensitive to the inhibitors of mitochondrial electron transport chain. Map-based cloning and transgenic functional confirmation revealed that NLG1 encodes a mitochondrial import inner membrane translocase containing a subunit Tim21. GUS staining assay and RT-qPCR suggested that NLG1 was mainly expressed in leaves and panicles. The expression level of respiratory function and auxin response related genes were significantly down-regulated in nlg1, which may be responsible for the declination of ATP production and auxin content.ConclusionsThese results suggested that NLG1 plays an important role in the regulation of leaf and grain size development by maintaining mitochondrial homeostasis. Our finding provides a novel insight into the effects of mitochondria development on leaf and grain morphogenesis in rice.

English

Narrow brown leaf spot disease of rice caused by fungus Cercospora oryzae Miyake emerged as potential threat to rice crop in previous few years worldwide and can cause more than 40% yield loss. The disease symptoms were noted on various commercially important rice varieties in the rice growing districts of Punjab province of Pakistan. Hence, the studies were planned to assess the effects of Propiconazole fungicide application timings and different rice varieties on the severity of narrow brown leaf spot (NBLS) disease of rice to develop an accurate management strategy for the disease. The Propiconazole fungicide was tested at three various growth phases (early booting, late booting, and soft dough) of four rice varieties against the percent severity of the NBLS disease The experiments were designed under strip-plot (crisscross) design with four replications at research area of Plant Pathology Department, University of Agriculture Faisalabad. Analysis of variance has demonstrated that the main and interactive effects of fungicide applications and rice varieties were found significant. The main effects of years were found non-significant but their interactions with fungicide application timings and rice varieties were significant. Fungicide applications at soft dough and late booting phases of rice variety B-515 were found least effective to reduce the disease severity, respectively. Fungicide application at early booting of rice variety PK-1121 was found most effective by reducing the maximum percent diseases severity (47.25%) compared to control. It is concluded that, to minimize hazardous effects of chemicals on the environment by practicing multiple sprays at inappropriate growth phases of rice crop, fungicides must be applied during the early and late booting phases of rice varieties on mildly resistance, susceptible and highly susceptible rice varieties to reduce NBLS disease severity and to enhance the rice production and quality

Occurrence of leaf spot caused by Stemphylium vesicarium on Red Clover (Trifolium pratense) in China.

Red clover (Trifolium pratense) is becoming increasingly important in grassland systems (sheep and beef) due to its high productivity, protein content and nitrogen-fixing ability which allows lower N fertilizer use (Murray et al. 2007). In June 2021, an unidentified foliar disease occurred seriously in experimental fields of red clover (25.61°N, 102.48°E) in Kunming city, Yunnan Province, China. Disease incidence was approximately 55% with an average disease severity of 41.1% in the fields (about 1.5 ha). Initially, the symptoms consisted of cicular to oval leaf spots with dark brown edges. In severely diseased plots, the diseased spots continued to expand and fuse along the leaf veins, forming long and narrow leaf spots, and the middle of the leaves were decayed and hollow. To isolate the pathogen, small pieces (3×3 mm) from the margin of infected lesions were surface-sterilized in 75% ethanol solution for 30 s, 1% NaClO solution for 90 s, rinsed three times with sterilized distilled water, air dried, and plated onto potato dextrose agar (PDA). The same fungus was isolated in 90% of the samples and purified by transferring the hyphal tip from the edge of colonies to fresh PDA plates. The colonies produced relatively dense light-grayish aerial mycelium in the early stage, which turned grayish upon mature, and then dark brown on the back of the colonies with dense small black patches. Conidiophores were unbranched, straight or flexuous, accompanied by slight or obvious swelling of its apical cells. Conidia were olive brown, irregularly round, 1 to 3 transverse septa, 0 to 2 longitudinal or oblique septa, and measured 16.0 - (24.8)- 30.1 × 13.9 - (21.4) - 28.6 µm (n = 50). Morphological characteristics were consistent with those described for Stemphylium vesicarium (Simmons, 1967). For molecular identification, total genomic DNA was isolated from mycelia collected from 6 day-old colonies of three representative isolates LZQF-1-LZQF-3 using the Omega D3195 fungal genomic DNA extraction kit. Fragments of three genes, including those encoding the ITS region of rDNA, calmodulin gene (cmdA), and glyceraldehyde-3-phosphate dehydrogenase (gpd) regions of isolates LZQF-1-LZQF-3 were amplified by the primers described previously (Woudenberg et al. 2017) and sequenced. Resulting sequences of representative strain LZQF-1 were deposited in GenBank with accession numbers of OL615093 (ITS), OL624541 (cmdA) and OL624538 (gpd), respectively. A nucleotide BLAST search revealed ITS, cmdA and gpd sequences to be 100%, 100% and 99.0% similar to the corresponding sequences (accessions numbers KU850563.1, KU850853.1 and KU850710.1) of ex-type strain CBS 370.51 of S. vesicarium. The three locus datasets were combined by SequenceMatrix 1.8 (Vaidya et al. 2011), and the strain LZQF-1-LZQF-3 and S. vesicarium (CBS 192.86, CBS 370.51 and CBS 205.82) formed a subclade with 99% bootstrap support. Pathogenicity tests were performed on LZQF-1 in a greenhouse at 18 °C-26 °C with 75% relative humidity. Three pots each containing three 50-day-old red clover were sprayed with the conidial suspension (3 × 105 conidia/ml) while another three pots were sprayed with sterile water as a control. Two weeks later, the inoculated leaves showed oval leaf spots with dark brown edges, distinctive symptoms of S. vesicarium infection. S. vesicarium was reisolated and confirmed by morphological and molecular features. There were no symptoms on the control leaves. S. vesicarium as a pathogen causing leaf spot disease has been reported on red clover in Canada (Jasalavich et al. 1995) and in Russia (Babuschkina et al. 1995). To our knowledge, this is the first report of leaf spot of red clover caused by S. vesicarium in China. The identification of Stemphylium leaf spot lays the groundwork for future investigations into epidemiology and management of S. vesicarium on red clover.

Assessing narrow brown leaf spot severity and fungicide efficacy in rice using low altitude UAV imaging

The utilization of unmanned aerial vehicle (UAV)-based imaging systems offers precise detection of plant diseases and aids in decision-making regarding fungicide applications to optimize disease control. This study employed a twin-lens multispectral camera mounted on a low-altitude UAV to capture imagery data from rice field plots that were treated with different fungicides. The objectives of this study were to assess the severity of narrow brown leaf spot (NBLS) caused by Cercospora janseana and to evaluate the efficacy of fungicide control. Eighteen color features and vegetation indices were extracted from RGB images, while nine color features and vegetation indices were extracted from multispectral images. Through correlation analysis, four spectral features, namely Lab-a, ExGR, VDVI, and g, were found to exhibit high correlations with disease severity. Specifically, RGB imagery had greater correlation coefficients (exceeding 0.95) for both ExGR and Lab-a features compared to multispectral imagery. A multifeature inversion modeling approach was employed, using support vector regression with the top four spectral features to predict NBLS severity. The results indicated R2 values were above 0.93 for all support vector regressions. Furthermore, the efficacies of ten different fungicide treatments were evaluated, with UAV imaging consistently aligning with ground truth rating data in terms of efficacy ranking. These results demonstrate the potential of UAV imagery for use as a valuable tool for NBLS detection and assessing fungicide efficacy, offering significant benefits in the management of NBLS, which is a globally important disease in rice.

Effect of Nutrient Management and Weeds on Incidence of Fungal Diseases in Rice

High-input, modern agriculture uses large amounts of energy, water, fertilizers, and pesticides to produce high crop yields. One of the major bottlenecks of the modern agriculture in the tropics is substantial yield losses due to fungal diseases including rice blast, leaf spots and leaf scald. The aim of this study was to compare the incidence of fungal diseases in judicious nutrient management systems, including organic, integrated, and conventional, under different weed categories during dry season (May to September 2020) and wet season (November 2020 to March 2021). Rice disease incidence were collected for both seasons from 48-84 days after sowing. Additionally, disease incidences on grasses and sedges weeds were also calculated. Brown spot, narrow brown leaf spot, leaf scald, and rice blast incidences were substantial in wet season, while the disease incidences during dry season in 2020 were negligible. The disease incidences were significantly higher (P<0.05) in organic and conventional input systems compared to the integrated input system. Disease incidences of brown spot and leaf scald were found in the dry season. Higher disease incidences were recorded in the wet season than in the dry season. The incidences of the brown spot were higher on sedges than in grasses and vice versa were observed for narrow brown leaf spot disease. Leaf scald incidences were positively correlated with the significant nitrogen status of the rice crop. Disease incidence was low in integrated input system compared to conventional and organic input systems, while weeds were reported as alternative hosts. It can be concluded that the integrated nutrient management with recommended dosage of nitrogen application with proper weed management can lead to low disease incidents, hence is ecologically more sustainable.

Serine protease NAL1 exerts pleiotropic functions through degradation of TOPLESS-related corepressor in rice.

NARROW LEAF 1 (NAL1) is a breeding-valuable pleiotropic gene that affects multiple agronomic traits in rice, although the molecular mechanism is largely unclear. Here, we report that NAL1 is a serine protease and displays a novel hexameric structure consisting of two ATP-mediated doughnut-shaped trimeric complexes. Moreover, we identified TOPLESS-related corepressor OsTPR2 involved in multiple growth and development processes as the substrate of NAL1. We found that NAL1 degraded OsTPR2, thus modulating the expression of downstream genes related to hormone signalling pathways, eventually achieving its pleiotropic physiological function. An elite allele, NAL1A, which may have originated from wild rice, could increase grain yield. Furthermore, the NAL1 homologues in different crops have a similar pleiotropic function to NAL1. Our study uncovers a NAL1-OsTPR2 regulatory module and provides gene resources for the design of high-yield crops.

A high-quality assembled genome of a representative peach landrace, ‘Feichenghongli’, and analysis of distinct late florescence and narrow leaf traits

BackgroundPeach (Prunus persica L. Batsch) is one of the most popular fruits worldwide. Although the reference genome of ‘Lovell’ peach has been released, the diversity of genome-level variations cannot be explored with one genome. To detect these variations, it is necessary to assemble more genomes.ResultsWe sequenced and de novo assembled the genome of ‘Feichenghongli’ (FCHL), a representative landrace with strict self-pollination, which maintained the homozygosity of the genome as much as possible. The chromosome-level genome of FCHL was 239.06 Mb in size with a contig N50 of 26.93 Mb and only 4 gaps at the scaffold level. The alignment of the FCHL genome with the reference ‘Lovell’ genome enabled the identification of 432535 SNPs, 101244 insertions and deletions, and 7299 structural variants. Gene family analysis showed that the expanded genes in FCHL were enriched in sesquiterpenoids and triterpenoid biosynthesis. RNA-seq analyses were carried out to investigate the two distinct traits of late florescence and narrow leaves. Two key genes, PpDAM4 and PpAGL31, were identified candidates for the control of flower bud dormancy, and an F-box gene, PpFBX92, was identified as a good candidate gene in the regulation of leaf size.ConclusionsThe assembled high-quality genome could deepen our understanding of variations among diverse genomes and provide valuable information for identifying functional genes and improving the molecular breeding process.

Narrow and Stripe Leaf 2 Regulates Leaf Width by Modulating Cell Cycle Progression in Rice

BackgroundLeaf morphology is an important component of the idea plant architecture that extensively influences photosynthesis, transpiration, and ultimately grain yield in crops. However, the genetic and molecular mechanisms regulating this morphology remain largely unclear.ResultsIn this study, a mutant showing a narrow and stripe leaf phonotype, designated nsl2, was obtained. Histological analysis revealed defects in the vascular system and reduced epidermal cell number in the nsl2, while the cell size remained unchanged. Map-based cloning and genetic complementation experiments revealed that NSL2, which encodes a small subunit of ribonucleotide reductases (RNRs), is a null allelic with ST1 and SDL. The NSL2 was expressed in variety of tissues, with the highest levels detected in leaves, and its protein was localized in the nucleus and cytoplasm. The dNTPs level was altered in the nsl2 mutant, and thereby affecting the dNTPs pool balance. In addition, flow cytometric analysis and the altered transcript level of genes related to cell cycle indicated that NSL2 affects cell cycle progression.ConclusionsOur findings here suggest that NSL2 function in the synthesis of dNTP, the deficient of which leads to DNA synthesis block and in turn affects cell cycle progression, and ultimately decreased cell number and narrow leaf in the nsl2 plant.

Multi-model genome-wide association studies of leaf anatomical traits and vein architecture in rice.

The anatomy of rice leaves is closely related to photosynthesis and grain yield. Therefore, exploring insight into the quantitative trait loci (QTLs) and alleles related to rice flag leaf anatomical and vein traits is vital for rice improvement. Here, we aimed to explore the genetic architecture of eight flag leaf traits using one single-locus model; mixed-linear model (MLM), and two multi-locus models; fixed and random model circulating probability unification (FarmCPU) and Bayesian information and linkage disequilibrium iteratively nested keyway (BLINK). We performed multi-model GWAS using 329 rice accessions of RDP1 with 700K single-nucleotide polymorphisms (SNPs) markers. The phenotypic correlation results indicated that rice flag leaf thickness was strongly correlated with leaf mesophyll cells layer (ML) and thickness of both major and minor veins. All three models were able to identify several significant loci associated with the traits. MLM identified three non-synonymous SNPs near NARROW LEAF 1 (NAL1) in association with ML and the distance between minor veins (IVD) traits. Several numbers of significant SNPs associated with known gene function in leaf development and yield traits were detected by multi-model GWAS performed in this study. Our findings indicate that flag leaf traits could be improved via molecular breeding and can be one of the targets in high-yield rice development.

Habitats and nesting habits of Streaked Weaver Ploceus manyar in select wetlands in the northern districts of Tamil Nadu, India

The habitats and nesting habits of Streaked Weaver Ploceus manyar was studied in the Narrow Leaf Cattail Typha angustifolia (Typhaceae) wetlands in Ranipet, Kancheepuram, and Viluppuram districts of northern Tamil Nadu. A total of 349 nests, in various developmental stages, in 24 colonies and of 536 adult individuals were enumerated. Of these 349 nests, 43 nests were in wad stage, 28 in ring stage, 123 in helmet stage, 55 egg-chamber-closed stage, and 100 complete nests including two abnormal nests were recorded. Streaked Weaver used fibres of T. angustifolia for building nests. Females were also observed to be engaged in nest construction, while males placed blobs of cow dung on the inner or both walls of helmet stage nests before pairing with females; 88.7% helmet stage nests had deposition of cow dung on their inner walls and the remaining 11.3% nests had no such deposits. In 59% nests the entrance tubes were found facing east. They showed communal foraging and the flock size ranged from 50─80 birds. No antagonistic interactions were observed between Streaked Weavers and other species over sharing of common perching sites and foraging grounds. Harvesting of nest-supporting reeds and sightings of avian predators, such as House Crow Corvus splendens, Large-billed Crow Corvus macrorhynchos, and Rufous Treepie Dendocitta vagabunda near nest colonies may pose threats to Streaked Weavers.

Effect of mulch on yield of groundnut (Arachis hypogaea) in Nepal

Weeds are the most important biotic constraints to groundnut production in Nepal. They hinder the plant growth and increase the cost of production. A field based study was conducted from June, 2022 to December, 2022 at Oilseed Research Program, Sarlahi, Nepal to study the effect of mulch on the productivity of groundnut. The experiment was laid out in randomized complete block design with 7 treatments viz., rice husk, rice straw, black polythene sheet, Lantana camara, living mulch, sawdust and control in three replications. The fertilizer dose used for groundnut was 20:40:20 NPK kg per hectare. The pod yield in rice husk mulch and living mulch treatments were significantly higher (2.07 and 1.84 tons per hectare, respectively) whereas the lowest yield (0.83 tons/hectare) was observed in plot with no treatment). Lower weed infestation with weed biomass 0.046 tons/ha for narrow leaf weeds and 0.021 tons/ha for broad leaf weeds was observed in L. camara mulching. Rice husk mulching produced significantly higher number of pods (29 pods per plant) with the highest benefit cost ratio (1.15) whereas black polythene mulching produced lower number of pods (23 pods per plant) with lowest benefit cost ratio (-0.33). Conclusively, the study's finding suggests that rice husk can be used as a mulching material to increase the productivity of groundnut.

Effect of genotypes and foliar spray of methyl jasmonate and salicylic acid on andrographolide yield in Andrographis paniculata (Burm. f.) Wall. ex Nees. under semi-arid climate

BackgroundAndrographis paniculata (Burm. f.) Wall. ex Nees. is an important medicinal plant grown in tropical and sub-tropical regions where semi-arid condition restricts economically viable cultivation. Foliar exogenous application of methyl jasmonate (MeJ) and salicylic acid (SA) was tested for their effectiveness in preventing yield loss in five different morphotypes of A. paniculata subjected to deficit soil moisture stress imposed during 90–140 days after transplanting.ResultsSoil moisture content below 6% reduced chlorophyll and carotenoid content and upregulated antioxidant enzymes activity. The dry herbage yield was adversely affected by deficit soil moisture stress causing a 14% decline. The andrographolide concentration ranged between 1.40% and 1.54%. Though andrographolide concentration increased by 6%, andrographolide yield declined by 8.21% due to soil moisture stress. Moderately high doses of MeJ and SA reduced chlorophyll and carotenoid content and upregulated antioxidant enzymes activity, however, failed to prevent the loss in dry herbage yield or total andrographolide yield in any morphotype.ConclusionsFoliar application of MeJ and SA do not warrant any protection against stress induced yield loss in field grown A. paniculata. However, morphotype AP 13 (round canopy, open-type branch, long narrow leaf) and AP 35 (columnar canopy, closed-type branch, long broad leaf) for having comparatively high herbage yield remained at a better position for total andrographolide yield under deficit soil moisture stress in the semi-arid climate.