Internode Length Research Articles

Jasmonate mimic modulates cell elongation by regulating antagonistic bHLH transcription factors via brassinosteroid signaling.

Lodging restricts growth, development, and yield formation in maize (Zea mays L.). Shorter internode length is beneficial for lodging tolerance. However, although brassinosteroids (BRs) and jasmonic acid (JA) are known to antagonistically regulate internode growth, the underlying molecular mechanism is still unclear. In this study, application of the JA mimic coronatine (COR) inhibited basal internode elongation at the jointing stage and repressed expression of the cell wall-related gene XYLOGLUCAN ENDOTRANSGLUCOSYLASE/HYDROLASE 1 (ZmXTH1), whose overexpression in maize plants promoted internode elongation. We demonstrated that the basic helix-loop-helix (bHLH) transcription factor ZmbHLH154 directly binds to the ZmXTH1 promoter and induces its expression, whereas the bHLH transcription factor ILI1 BINDING BHLH 1 (ZmIBH1) inhibits this transcriptional activation by forming a heterodimer with ZmbHLH154. Overexpressing ZmbHLH154 led to longer internodes, whereas zmbhlh154 mutants had shorter internodes than the wild type. The core JA-dependent transcription factors ZmMYC2-4 and ZmMYC2-6 interacted with BRASSINAZOLE RESISTANT 1 (ZmBZR1), a key factor in BR signaling, and these interactions eliminated the inhibitory effect of ZmBZR1 on its downstream gene ZmIBH1. Collectively, these results reveal a signaling module in which JA regulates a bHLH network by attenuating BR signaling to inhibit ZmXTH1 expression, thereby regulating cell elongation in maize.

Application of silvicultural treatments to improve local Gigantochloa apus (Schult. & Schult.f.) Kurz ex Munro stands for supporting handicraft industries in Gunungkidul region, Indonesia

There is a growing demand within the Gunungkidul region of Indonesia for bamboo, particularly Gigantochloa apus (Schult.f.) Kurz ex Munro, which is used in handicrafts. This study examined ways to enhance the productivity of bamboo to meet the specific requirements of the craft industry in the region. It assessed the impact of three levels of thinning intensity and three types of fertilizer application on the productivity and quality of G. apus. The type of fertilizer application significantly influenced the diameter of the sixth internode and the overall height of the bamboo while having an insignificant effect on the number of bamboo shoots, internode diameter at one meter or internode length. Thinning intensity significantly affected several aspects, including the number of shoots, the diameter of the sixth internode and the overall height of the bamboo. Clump thinning intensity increased the diameter of the remaining bamboo clump but reduced the number of shoots, as well as internode length and overall height. The interaction between thinning intensity and fertilizer application significantly impacted the diameter of bamboo, the diameter of the sixth internode, and the overall height of bamboo, without significant effects on the number of shoots or the internode length.

Transcriptional Regulation and Gene Mapping of Internode Elongation and Late Budding in the Chinese Cabbage Mutant lcc.

Two important traits of Chinese cabbage, internode length and budding time, destroy the maintenance of rosette leaves in the vegetative growth stage and affect flowering in the reproductive growth stage. Internodes have received much attention and research in rice due to their effect on lodging resistance, but they are rarely studied in Chinese cabbage. In Chinese cabbage, internode elongation affects not only the maintenance of rosette leaves but also bolting and yield. Budding is also an important characteristic of Chinese cabbage entering reproductive growth. Although many studies have reported on flowering and bolting, studies on bud emergence and the timing of budding are scarce. In this study, the mutant lcc induced by EMS (Ethyl Methane Sulfonate) was used to study internode elongation in the seedling stage and late budding in the budding stage. By comparing the gene expression patterns of mutant lcc and wild-type A03, 2280 differentially expressed genes were identified in the seedling stage, 714 differentially expressed genes were identified in the early budding stage, and 1052 differentially expressed genes were identified in the budding stage. Here, the transcript expression patterns of genes in the plant hormone signaling and clock rhythm pathways were investigated in relation to the regulation of internode elongation and budding in Chinese cabbage. In addition, an F2 population was constructed with the mutants lcc and R500. A high-density genetic map with 1602 marker loci was created, and QTLs for internode length and budding time were identified. Specifically, five QTLs for internode length and five QTLs for budding time were obtained. According to transcriptome data analysis, the internode length candidate gene BraA02g005840.3C (PIN8) and budding time candidate genes BraA02g003870.3C (HY5-1) and BraA02g005190.3C (CHS-1) were identified. These findings provide insight into the regulation of internode length and budding time in Chinese cabbage.

A Genome-Wide Analysis of the CEP Gene Family in Cotton and a Functional Study of GhCEP46-D05 in Plant Development.

C-TERMINALLY ENCODED PEPTIDEs (CEPs) are a class of peptide hormones that have been shown in previous studies to play an important role in regulating the development and response to abiotic stress in model plants. However, their role in cotton is not well understood. In this study, we identified 54, 59, 34, and 35 CEP genes from Gossypium hirsutum (2n = 4x = 52, AD1), G. barbadense (AD2), G. arboreum (2n = 2X = 26, A2), and G. raimondii (2n = 2X = 26, D5), respectively. Sequence alignment and phylogenetic analyses indicate that cotton CEP proteins can be categorized into two subgroups based on the differentiation of their CEP domain. Chromosomal distribution and collinearity analyses show that most of the cotton CEP genes are situated in gene clusters, suggesting that segmental duplication may be a critical factor in CEP gene expansion. Expression pattern analyses showed that cotton CEP genes are widely expressed throughout the plant, with some genes exhibiting specific expression patterns. Ectopic expression of GhCEP46-D05 in Arabidopsis led to a significant reduction in both root length and seed size, resulting in a dwarf phenotype. Similarly, overexpression of GhCEP46-D05 in cotton resulted in reduced internode length and plant height. These findings provide a foundation for further investigation into the function of cotton CEP genes and their potential role in cotton breeding.

Characterization of genetic diversity of greens‐type hybrid bermudagrass selections through SSR markers and morphological analysis

AbstractThe development of Tifgreen bermudagrass, and the subsequent mutations of this cultivar, has revolutionized the game of golf in the southern United States as superintendents have access to high‐quality putting surface capable of withstanding hot summers. However, the lack of genetic diversity may make them vulnerable to various pests and the low tolerance to freeze temperatures may make them susceptible to winterkill. In recent years, Oklahoma State University and other universities have begun to create new interspecific F1 hybrids between common (Cynodon dactylon) and African bermudagrasses (C. transvaalensis) for putting greens. The objectives of this study were to investigate the genetic diversity and variation among 14 experimental genotypes and two standard cultivars (TifEagle and Tifdwarf). Simple sequence repeat (SSR) markers and morphological characteristics were used to evaluate the genetic relationships and variation among the 16 genotypes. Results showed significant variation for 11 vegetative traits and two reproductive traits. The phenotypic coefficient of variation was greatest for the third internode length and the least for the first leaf angle for both the field and greenhouse trials. The morphological cluster analysis also showed variation between the two trial environments. The SSR marker cluster analysis showed the 16 genotypes were grouped into four major groups, with a similarity coefficient ranging from 0.44 to 1. The highest similarity was found among the two commercial standards and an experimental ultradwarf from Florida. Several new genotypes (OKC3920, 5 × 23, 11 × 2, 19 × 19, and 34 × 20) were also grouped with the ultradwarf genotypes in the morphological cluster analysis, showing the possibility of achieving similar morphological traits with new genetics. Further field evaluations are needed to determine the performance of these genotypes under low mowing heights.

Assessment of the changes in growth, photosynthetic traits and gene expression in Cynodon dactylon against drought stress

Drought stress considered a key restrictive factor for a warm-season bermudagrass growth during summers in China. Genotypic variation against drought stress exists among bermudagrass (Cynodon sp.), but the selection of highly drought-tolerant germplasm is important for its growth in limited water regions and for future breeding. Our study aimed to investigate the most tolerant bermudagrass germplasm among thirteen, along latitude and longitudinal gradient under a well-watered and drought stress condition. Current study included high drought-resistant germplasm, “Tianshui” and “Linxiang”, and drought-sensitive cultivars; “Zhengzhou” and “Cixian” under drought treatments along longitude and latitudinal gradients, respectively. Under water deficit conditions, the tolerant genotypes showed over-expression of a dehydrin gene cdDHN4, antioxidant genes Cu/ZnSOD and APX which leads to higher antioxidant activities to scavenge the excessive reactive oxygen species and minimizing the membrane damage. It helps in maintenance of cell membrane permeability and osmotic adjustment by producing organic osmolytes. Proline an osmolyte has the ability to keep osmotic water potential and water use efficiency high via stomatal conductance and maintain transpiration rate. It leads to optimum CO2 assimilation rate, high chlorophyll contents for photosynthesis and elongation of leaf mesophyll, palisade and thick spongy cells. Consequently, it results in elongation of leaf length, stolon and internode length; plant height and deep rooting system. The CdDHN4 gene highly expressed in “Tianshui” and “Youxian”, Cu/ZnSOD gene in “Tianshui” and “Linxiang” and APX gene in “Shanxian” and “Linxiang”. The genotypes “Zhongshan” and “Xiaochang” showed no gene expression under water deficit conditions. Our results indicate that turfgrass show morphological modifications firstly when subjected to drought stress; however the gene expression is directly associated and crucial for drought tolerance in bermudagrass. Hence, current research has provided excellent germplasm of drought tolerant bermudagrass for physiological and molecular study and future breeding.

Adaptation and growth performance of different bamboo species in Dryland areas of Northern Ethiopia

Bamboos are among the large perennial grasses that are renowned for their remarkable vigor and quick development. However, the amount of bamboo available in natural settings is decreasing as a result of shifting agriculture, overexploitation, and forest fires. Furthermore, there is little genetic diversity in our country because just two species are found in a small number of agroecological zones. This makes it difficult to guarantee a steady supply of bamboo, despite its benefits to the environment and economy. Thus, the goal of this study was to evaluate the adaptability and growth performance of four bamboo species: Oxytenanthera abyssinica (A.Rich.) Munro, Phyllostachys edulis (Carrière) J Houz, Bambusa vulgaris Schrad. ex J.C. Wendl, and B-ambusa bambos (L) Voss'. The study was carried out at the Mekelle Agricultural Research Center compound for four years, from 2020 to 2023. Three replications of a strict RCBD design were used in the experiment. There were four plants each plot, for a total of 48 plants, and there was a three-meter gap between each plant and plot. A range of growth indicators, including new shoot emergence, culm diameter, internode length, culm height, and survival rate, were measured at three-month intervals in order to monitor changes among the species. B. bambos, B. vulgaris, and O. abyssinica showed no problems with survival or adaptation in the research locations, with the exception of small growth variances. Significant changes (p≤ 0.05) in the treatment parameters were shown by the statistical analysis. O. abyssinica displayed a noticeably greater quantity of freshly emerging bamboo shoots in comparison to other bamboo species. Conversely, P. edulis showed the lowest growth metrics in terms of internode length, culm height, culm diameter, and survival rate. P. edulis, B. vulgaris, O. abyssinica, and B. bambos had survival rates of 16.67 percent, 66.67 percent, 75 percent, and 91.67 percent, respectively. It is noteworthy that seasonal differences have a substantial impact on the height of culms and the growth of newly emergent shoots. B. vulgaris, B. bambos, and O. abyssinica all showed good growth and survival rates. As a result, it is advised to highlight and promote these species in related agroecological areas, as this can benefit multiple stakeholders’ livelihoods and economies.

The Short Inflorescence Mutation in Diploid Strawberry Fragaria vesca Affects Inflorescence Architecture and Runner Elongation

Mutants are useful for determining the genes that underlie a given trait. This information is highly useful for developing molecular markers for breeding and is the foundational knowledge required for future genomic crop improvements. The dessert strawberry, Fragaria ×ananassa, is a valuable crop with high potential for increased use in controlled environment agriculture. The genome of the woodland strawberry Fragaria vesca is the dominant genome of the four diploid strawberry subgenomes that contribute to the octoploid F. ×ananassa genome. F. vesca is therefore a useful reference system for determining gene function and should be a useful source of gene diversity for breeding of F. ×ananassa. Chemical mutagenesis of the inbred F. vesca line H4 F7-3 resulted in one M2 line with a smaller stature overall and which produces flowers on very short peduncles close to the crown. This line was named short inflorescence (sin). The sin phenotype results from a single gene recessive mutation that is pleiotropic in that the mutation also affects internode lengths of runners as well as petiole elongation of sin plants. Microscopic characterization revealed that sin peduncles are most likely short because of a failure of cells to elongate. Inflorescences, runners, and petioles of sin plants were found to elongate in response to exogenous gibberellin, indicating that sin could be a gibberellin biosynthesis or transport mutant. A brief characterization of sin plants is presented to facilitate collaborative studies of the line.

Variation of fruit morphology and genetic divergence of indigenous pointed gourd

Thirty one indigenous pointed gourd genotypes were studied in Terai region of West Bengal, India to observe variation of fruit morphology and genetic divergence using Mahalanobis D2 statistics and principal component analysis. The field experiment was designed in RBD with three replications at Uttar Banga Krishi Viswavidyalaya, West Bengal, India during the year 2018-19and 2019-20. All the genotypes were arranged into eight divergent clusters in which cluster I included maximum number followed by cluster II. The highest contribution towards genetic diversity was shown for node at the first female flower (37.85%) followed bychlorophyll a content of leaf (16.77%) and seeds per fruit (12.04%). Principal component-1 had maximum variability (43.83%) with positive loading for the characters like node at the first female flower (0.298), appearance of first female flower (0.265), days to fruit maturity (0.194) and internodal length (0.137). Based on the inter and intra cluster distance cross combinations in between lines PCP-17 and PCP-19, PCP-17 and PCP-9, PCP-17 and PCP-28, PCP-19 and PCP-11, PCP-14 and PCP-9 and PCP-23 and PCP-10 may be utilized in future improvement programme of pointed gourd. Bangladesh J. Bot. 53(1): 193-201, 2024 (March)

Cloning and functional mechanism of the dwarf gene gba affecting stem elongation and cellulose biosynthesis in jute (Corchorus olitorius).

Plant height (PH) is an important factor affecting bast fiber yield in jute. Here, we report the mechanism of dwarfism in the 'Guangbaai' (gba) of jute. The mutant gba had shorter internode length and cell length compared to the standard cultivar 'TaiZi 4' (TZ4). Exogenous GA3 treatment indicated that gba is a GA-insensitive dwarf mutant. Quantitative trait locus (QTL) analysis of three PH-related traits via a high-density genetic linkage map according to re-seq showed that a total of 25 QTLs were identified, including 13 QTLs for PH, with phenotypic variation explained ranging from 2.42 to 74.16%. Notably, the functional mechanism of the candidate gene CoGID1a, the gibberellic acid receptor, of the major locus qPHIL5 was evaluated by transgenic analysis and virus-induced gene silencing. A dwarf phenotype-related single nucleotide mutation in CoGID1a was identified in gba, which was also unique to the dwarf phenotype of gba among 57 cultivars. Cogid1a was unable to interact with the growth-repressor DELLA even in the presence of highly accumulated gibberellins in gba. Differentially expressed genes between transcriptomes of gba and TZ4 after GA3 treatment indicated up-regulation of genes involved in gibberellin and cellulose synthesis in gba. Interestingly, it was found that up-regulation of CoMYB46, a key transcription factor in the secondary cell wall, by the highly accumulated gibberellins in gba promoted the expression of cellulose synthase genes CoCesA4 and CoCesA7. These findings provide valuable insights into fiber development affected by endogenous gibberellin accumulation in plants.

Distribution, morphology, and phenology of Piper acutistigmum C. DC. – an endemic species of the Eastern Himalayan region

Piper acutistigmum C. DC. is an endemic species of the Eastern Himalayan region found in northeast India with the adjacent country Myanmar. A study was conducted to examine the distribution, morphology, and phenology of the species, which is an important step towards its conservation. Field surveys were conducted to locate the population, and observations were made on selected plants from three distinct locations. The study revealed that the species is mostly found in the foothills of Arunachal Pradesh and its bordering areas in Assam. The orthotropic and plagiotropic branches show distinct differences in terms of leaf size and shape, petiole, and internodal length. The average sizes of the leaves were 10 × 6 cm and 21.5 × 12.5 cm; petiole length was 3.7 cm and 2.25 cm and internodal length was 17.5 and 6.5 cm in orthotropic and plagiotropic branches, respectively. Leaf flushing occurs between the March and April months, more or less in synchronization with the emergence of the spike bud. The species starts flowering from April until the end of May. The fruiting spikes are observed from July to December. Sterile vines are most dominant in a population with a few fertile (male and female) individuals. The existing natural population is under threat from various developmental activities in and around their habitat and needs immediate attention for conservation.

Unveiling the Regulatory Role of miRNAs in Internode Elongation: Integrated Analysis of MicroRNA and mRNA Expression Profiles across Diverse Dwarfing Treatments in Maize (Zea mays L.).

MicroRNAs are crucial regulators of gene expression in maize. However, the mechanisms through which miRNAs control internode elongation remain poorly understood. This study engineered varying levels of internode elongation inhibition, revealing that dwarfing treatments diminished gibberellin levels, curtailed cell longitudinal growth, and slowed the rate of internode elongation. Comprehensive transcriptome and miRNA profiling of the internode elongation zone showed gene expression changes that paralleled the extent of the internode length reduction. We identified 543 genes and 29 miRNAs with significant correlations to internode length, predominantly within families, including miR164 and miR396. By incorporating target gene expression levels, we pinpointed nine miRNA-mRNA pairs that are significantly associated with the regulation of the internode elongation. The inhibitory effects of these miRNAs on their target genes were confirmed through dual-luciferase reporter assays. Overexpression of miR164h in maize resulted in increased internode and cell length, suggesting a novel genetic avenue for manipulating plant stature. These miRNAs may also serve as precise spatiotemporal regulators for in vitro plant development.

Effects of green pruning and combine microelement applications on bud fruitfulness, vegetative development and cluster characteristics of ‘Trakya İlkeren’ grape cultivar

Green pruning practices are frequently used in viticulture. These practices provide better light penetration, successful air circulation, prevents air humidity and aids disease control in the grapevine canopy. However, excessive leaf removal inhibits vine growth and good fruit ripening. In this study, the effects of some foliar and canopy management practices on cluster, vegetative growth traits and bud fruitfulness of the following year were investigated. Some green pruning (unproductive shoot removal, leaf removal, shoot tip removal, shoot topping), foliar microelements and green pruning + microlements treatments were applied in ‘Trakya İlkeren’ grape cultivar. Microelement application increased cluster (382.1 g) and berry weight (4.4 g), berry length (19.7 mm) and width (18.2 mm), cluster length (19.5 cm) and width (13.9 cm), berry volume (3.30 cm3) and berry firmness (7.46 N). The highest maturity index was detected in the control group (23.4). While the most intense L* color value was determined in the green pruning + micro element application, the b* color value was determined in the green pruning application. It was determined that leaf area (211.2 cm2), leaf chlorophyll index (32.75 SPAD), shoot diameter (11.13 mm), shoot length (194.71 cm) and internode length (76.81 mm) increased with microelement application. Among the treatments, the most effective application on bud fruitfulness in the following year was at microelement application (1.34 clusters). The effects of the treatments on the amount of Total soluble solids pH, titratable acid and a* color value were not significant. In this study; green pruning + microelement application was recommended for yield and quality sustainability. According to bud fruitfulness results, the highest cluster numbers per node were obtained from pruning with 4 to 10 buds. It is recommended to prune medium or long to obtain higher yields from this cultivar.

The results of the variety testing of cannabis in the conditions of the Republic of Bashkortostan

Relevance. In recent years, this crop, which is cultivated in order to obtain oil and fiber, is gradually gaining its abundance, increasing the acreage. In many agro-industrial enterprises, hemp is being introduced into crop rotations, and plants for its processing are being built. This culture plays a huge national economic importance and finds its application in various industries. One of the main elements of cannabis cultivation technology is the use of highly productive varieties.Methodology. The laying of field experiments, related observations and records were carried out in accordance with existing methodological guidelines for conducting field and vegetation experiments with cannabis.Results. The most optimal variety for the conditions of the Southern forest-steppe zone of the Republic of Bashkortostan is the Nadezhda variety. This variety is superior to the others (Vera and Omegadar-1) in terms of quality and quantity. For example, from the 2021–2022 studies on biomorphometric indicators, it follows that Nadezhda achieved the best indicators for: plant height (194.50 cm and 194.33 cm), technical stem length (160.60 cm and 162.45 cm), inflorescence length (33.90 cm and 31.88 cm), stem diameter (0.8–0.9 cm), the number of internodes (8–9 pcs.), the average length of internodes (12.5 cm and 19.87 cm). The weight of 1000 seeds was 17.01 g and 18.10 g, oil content — 32.89% and 33.72%, yield — 0.88 t/ha and 1.71 t/ha. The greatest results in 2022 are associated with agrometeorological conditions.

How do novel plant growth regulators and cultivation models strategies affect mechanical strength, lodging resistance and maize productivity in semi-arid regions?

Plant growth regulators are synthetic compounds that have become a significant and technical guarantee for agricultural productivity. In China, "Jindeli", which contains active elements of ethephon and cycocel (EC), has been proven to prevent maize stem elongation, improve maize stem thickness, stem morphology and mechanical strength, root growth, lodging resistance, and yield under various cultivation models. Diethyl aminoethyl hexanoate (DA-6) can promote cell division and growth. From 2020–2021, four growth regulators sprays were used to conduct a field experiment; G1: water spraying; G2: EC spraying; G3: DA-6 spraying; G4: EC+DA-6 spraying under two cultivation models; R: ridge covered with plastic film mulching and T: traditional flat planting without plastic mulching. The results indicated that RG4 treatment considerably decreased plant height, internode length, ear height, lodging rate, and center of gravity height, while improved the internode bending strength, cross-sectional area, cortical thickness, and stem vascular bundles as compared with rest of all other treatments. RG4 treatment considerably improved internode diameter, stem mechanical strength, filling degree, root growth, mean tilt angle, and lignin content, while significantly reducing LAI. In addition, RG4 considerably enhanced the quality of corn stems, such as increasing mechanical properties and enhancing the compressive strength of corn stalks that content of hemicellulose, cellulose, and lignin has been increased. Furthermore, RG4 treatment significantly improved grain yield by optimizing leaf layer structure and increasing bleeding saps levels, increasing the grains per row and ear. Thus, under the RG4 treatment maize lodging rate was decreased 72.1%, and increased WUE (52.8%), and grain yield (46.6%). In conclusion, the results clearly demonstrate that in the semi-arid regions risk of lodging can be avoided by spraying EC+DA-6 with ridge covered plastic film mulching to the enriched stalk quality, shaping plant morphological characteristics, and proving a stable cultivation model to improving maize productivity.

Exploring multivariate associations of yield and yield-associated traits in okra (Abelmoschus esculentus (L.) Moench) accessions in the Northwestern Region of India

Evaluating genetic diversity simplifies the identification of superior genotypes, facilitating the development of high-yielding, resilient to climatic conditions and promoting effective crop improvement. The present study aimed to examine the divergence, correlation and path analysis across 55 okra (Abelmoschus esculentus (L.) germplasms for 17 traits during the summer season (March- July) of 2022. The experiment utilized randomized complete block design with three replications conducted in Phagwara, Punjab. Analysis of variance suggested a sufficient amount of genetic variation was found among all genotypes. Using Mahalanobis D2 analysis, the samples were classified into seven clusters, the largest being cluster I, composing 34 germplasm. Only one germplasm was found in Clusters II, IV, V, VI, and VII. The inter-cluster distance was highest between clusters II and VII, whereas the intra-cluster distance was greatest in Cluster III. The number of fruits per plant had the highest percent contribution to the divergence, accounting for 49.63%. At both phenotypic and genotypic levels, there was a strong positive correlation (+) observed between fruit yield and various characteristics, including plant height, fruit length, number of fruits per plant, number of marketable fruits per plant, average fruit weight, and the number of pickings. Genotypic path analysis revealed that characteristics such as the first flowering node, days to first flowering, days to 50% flowering, plant height, inter-nodal length, number of nodes per plant, number of fruits per plant, marketable fruits per plant, and average fruit weight exhibited a positive and direct effect on fruit yield. When selecting this trait to improve yield in okra through breeding, it is essential to focus on specific characteristics that directly contribute to higher production. This research will help resilient okra varieties understand yield-influencing factors in Punjab environmental conditions.

MiR156-PvSPL2 controls culm development by transcriptional repression of switchgrass CYTOKININ OXIDASE/DEHYDROGENASE4.

Culm development in grasses can be controlled by both miR156 and cytokinin. However, the crosstalk between the miR156-SPL module and the cytokinin metabolic pathway remains largely unknown. Here, we found CYTOKININ OXIDASE/DEHYDROGENASE4 (PvCKX4) plays a negative regulatory role in culm development of the bioenergy grass Panicum virgatum (switchgrass). Overexpression of PvCKX4 in switchgrass reduced the internode diameter and length without affecting tiller number. Interestingly, we also found that PvCKX4 was always upregulated in miR156 overexpressing (miR156OE) transgenic switchgrass lines. Additionally, upregulation of either miR156 or PvCKX4 in switchgrass reduced the content of isopentenyl adenine (iP) without affecting trans-zeatin (tZ) accumulation. It is consistent with the evidence that the recombinant PvCKX4 protein exhibited much higher catalytic activity against iP than tZ in vitro. Furthermore, our results showed that miR156-targeted SPL2 bound directly to the promoter of PvCKX4 to repress its expression. Thus, alleviating the SPL2-mediated transcriptional repression of PvCKX4 through miR156 overexpression resulted in a significant increase in cytokinin degradation and impaired culm development in switchgrass. On the contrary, suppressing PvCKX4 in miR156OE transgenic plants restored iP content, internode diameter, and length to wild-type levels. Most strikingly, the double transgenic lines retained the same increased tiller numbers as the miR156OE transgenic line, which yielded more biomass than the wild type. These findings indicate that the miR156-SPL module can control culm development through transcriptional repression of PvCKX4 in switchgrass, which provides a promising target for precise design of shoot architecture to yield more biomass from grasses.

Influence of Organic Manures and Foliar Application of Arka Citrus Special on the Growth of Buddlings of Sweet Orange

In India, citrus fruits rank third in area and production after Mango and Banana. A study was conducted at the Horticultural Research Station (HRS) Konda Mallepally, Nalgonda district during Rabi, November 2022 - April 2023. The study aimed to test the effects of organic manures and foliar application of Arka Citrus Special on the growth of sweet orange cv. Sathgudi buddlings. The experiment included fourteen treatments with three replications in RBD. It comprised three types of organic manures (FYM, Vermicompost, Neem cake) and Arka Citrus Special (micronutrient formulation). The application of organic manures and micronutrients showed significant differences in plant height (cm), number of leaves, and leaf area (cm2). During 30, 60, 90 and 120 days of observations, the maximum plant height (26.99 cm), stem diameter (1.23 mm), number of leaves (26.00), girth of the plant (19.5 mm), leaf area (11.70 cm2), internodal length (0.260 cm), absolute growth rate (0.42 cm /day) and relative growth rate (0.10 cm /cm /day).

Genetic variability and QTL mapping of morphological traits and inflorescence prolificacy in African bermudagrass

AbstractAfrican bermudagrass (Cynodon transvaalensis Burtt‐Davy) (2n = 2x = 18) has unique morphological characteristics such as finer leaf blades and shorter internodes that are important to improving turf qualities (i.e., texture and density) as compared to other Cynodon species. It has been extensively used to cross with common bermudagrass (Cynodon dactylon Pers. var. dactylon) in developing high‐quality interspecific [C. dactylon (L.) Pers. × C. transvaalensis Burtt‐Davy] F1 hybrid cultivars for turf use. However, the molecular basis of its morphological variation is unknown. Accordingly, the objectives of this study were to estimate the heritability and identify quantitative trait loci (QTL) associated with morphological and reproductive traits. A first‐generation self‐pollinated (S1) population of 109 individuals was evaluated for plant height (PH), leaf blade width (LBW) and leaf blade length, stem internode diameter and length, and inflorescence prolificacy (IP) in a replicated field trial over three seasons (2018–2020). The broad‐sense heritability estimates ranged from 0.31 (PH) to 0.80 (IP). Twenty‐four QTL were identified and nine of them were consistent ones. Fifteen candidate genes were found at a major and consistent QTL region associated with LBW. Frequent QTL colocations were found among morphological traits and between morphological traits and IP, partially explaining the significant correlation. The findings provide critical information and resources toward understanding the genetic basis associated with morphological and reproductive traits within C. transvaalensis and could contribute to marker‐assisted selection for breeding new turf‐type bermudagrass cultivars.

Effect of planting density on yield and architecture suitability of groundnut (Arachis hypogaea) varieties

A field experiment was conducted during rainy (kharif) seasons of 2018 and 2019 at the research farm of Sri Venkateswara Agricultural College (Acharya N. G. Ranga Agricultural University), Tirupati, Andhra Pradesh, to study the effect of planting density on yield and architecture suitability of groundnut (Arachis hypogaea L.) varieties. The experiment included 4 sowing densities (D1, 33.3 plants/m2; D2, 50 plants/m2; D3, 66.6 plants/m2 and D4, 100 plants/m2) and 3 genotypes with varying architecture (G1, Kadiri 6-erect; G2, Kadiri 9-decumbent 2; and G3, Dharani-decumbent 3). The results showed that across planting densities, Dharani and Kadiri 9 genotypes showed higher architectural traits, structural carbohydrates and kernel yield compared to the Kadiri 6. A significant positive correlation was detected between the lodging percentage and both plant height (r = 0.88**) and internodal length (r = 0.61*). Significant negative correlations, were identified between lodging percentage and several parameters, including leaf thickness (r = -0.92**), specific leaf weight (r = -0.93**), stem diameter (r = -0.79**), specific stem weight (r = -0.97**), number of branches (r = -0.72**), cellulose content (r = -0.80**), and lignin content (r = -0.79**). These findings indicate that the decumbent architecture is optimal for achieving groundnut lodging resistance and kernel yield in high-density planting systems.