Development of Morphological Descriptors For Characterization of Teak (Tectona Grandis L. f.) Seed Sources In India

Teak (Tectona grandis L.f.) plantations in India has been intensified in the recent past yet, morphological descriptors for teak is still lacking. Hence, this study aimed to develop descriptors using morphological traits. Among 30 seed sources collected from different states of India, 24 morphological descriptors viz., leaf length, leaf width, presence of petiole, petiole length, leaf shape, shape of leaf apex, shape of leaf base, leaf texture, phyllotaxy, leaf attitude, leaf margin, leaf margin undulation, leaf brightness, leaf venation, leaf main vein, leaf veins, leaf vein colour, leaf colour, leaf pubescence, young leaf colour, number of internodes, internodal length, trunk spots and trunk colour were developed based on leaf and stem characteristics. Subsequently, genetic similarity among the sources were estimated by Jaccard similarity index and cluster analysis was performed by Unweighted Pair Group Method with Arithmetic mean (UPGMA) method.

Assessment of introgression wheat lines for yield, protein yield and resistance to diseases

Aim. To determine the value of breeding traits from new sources by studying the resistance to diseases, protein content and their relationship with the productivity of introgression wheat lines. Methods. Growing plants under infection backgrounds of wheat diseases was combined with the laboratory methods for determining protein content and weight of 1000 kernels. Results. Disease resistance has depended on the pathogen species and the source of alien variability. Prolonged resistance to stem rust has been observed only among the derivatives of the collection sample H74/90-245, containing the translocation 1BL.1RS in the karyotype and T. timopheevii in the pedigree. Derivatives Ae. tauschii gradually lost the resistance to the time of full maturation. Conclusions. The parameters of plant resistance to diseases, protein content and yield, absolute protein content in 1000 kernels should be used for the material selection. The best lines have been selected from 736 introgression lines. They characterized by high productivity in some years, large grain, high protein content, disease resistance, adaptability to local environments and devoid of the wild species negative qualities. The lines are of interest for further breeding work in the south of Ukraine. Lines with leaf pubescence from T. timopheevii and with modified translocation 1BL.1RSm were characterized by low productivity.Keywords: wheat, introgression lines, disease resistance, protein content, productivity.

Morphological Characterization of High Grain Iron and Zinc Concentration Bio-fortified lentil (Lens culinaris Medikus subsp. culinaris) in Nepal

Lentil (Lens culinaris Medikus subsp. culinaris) is the wonderful, most popular & preferred food legume of Nepalese people and commonly grown in the rice and maize based cropping system. Morphological characters have been frequently used in order to know the diversity in germplasm collections. The main objectives of the study were to characterize the bio-fortified lentil accessions using morphological markers and select the DUS accession for using targeted the best utilization in hybridization program. Plant breeders can use these morphological variations to make decision regarding the choice for selecting superior genotypes for improvement or to be utilized as parents for the development of future cultivars through hybridization. Furthermore, important morphological markers like, plant type, foliage color, testa color, testa pattern and cotyledon colors can also be used for testing hybridity and keeping genetic purity at genetic level. The information obtained by the identification keys at seed and plant levels may be useful for discrimination and verification of varieties, hybridity testing and maintenance of genetic purity at genetic level during seed production and certification programme. Out of 25 lentil accessions, 18 accessions were observed as erect and compact growth habit, 22 accessions had green stem color, 21 accessions had dense leaf pubescence and dark foliage, 7 accessions had prominent tendril, 3 accessions had white blue veins flower and 4 accessions had large seeded accession.

Correlation Analysis for Leaf Pubescence, Leaf Micro-macro Nutrient Content and MYMV Disease Index in Blackgramgenotypes (Vigna mungo (L.) Hepper)

The present field study was conducted to characterize the blackgram genotypes based on morpho and nutrient content under yellow mosaic virus disease infection. The present investigation was carried out with ten blackgram genotypes (5 known tolerant + 5 known susceptible) in Randomized Block Design (RBD) during summer 2018. Experimental crop was affected by yellow mosaic virus (YMV) naturally at 30 DAS. No management practices were taken for controlling of whitefly population during crop season. Correlation studies were done at 50 DAS which helps to find out the most resistant and most susceptible genotypes among ten backgram genotypes based on leaf pubescence and nutrient content in leaf. Leaf pubescence is one of the most important resistant factors in a number of crops and Minerals, apart from being a vital part of the plant nutrition, may manifest certain maladies in the plants either through disturbing normal metabolism and physiology of the plants or by favouring or by discouraging the plant pathogens, if in excess or otherwise deficient. Correlation analysis of present field investigation revealed that blackgram genotypes showed strong negative correlation for leaf pubescence, leaf Phosphorous (P) and leaf potassium (K) content with percentage disease index (PDI%) as well as strong positive correlation for leaf Nitrogen (N), leaf Iron (Fe) and leaf Zinc (Zn) content under YMV.

The identification of a new gene for leaf pubescence introgressed into bread wheat from Triticum timopheevii Zhuk. and its manifestation in a different genotypic background

Leaf pubescence is widespread among higher plants. In bread wheat, a relationship was found between this trait and the efficiency of photosynthetic processes and productivity. In this work, we established the chromosomal localization of the gene for leaf pubescence introgressed from Triticum timopheevii into a bread wheat line 821 and studied its expression in the genetic background of two wheat cultivars differing in genetic control and phenotypic expression of pubescence. To obtain quantitative characteristics of pubescence in cultivars and hybrid populations, the LHDetect2 program was used, which makes it possible to estimate the length and number of trichomes on a leaf fold. A genetic analysis showed the dominant inheritance of the gene. Monosomic analysis F2 was used to establish chromosome localization and investigate the expression of the gene in cultivars Saratovskaya S29 (S29) and Diamant 2 (Dm2). As a result, the gene Hltt, introgressed from T. timopheevii, was identified and localized in the distal region of the long arm of 5A chromosome for the first time. In both F2 populations, the gene reduced the density of trichomes and formed long trichomes, uncharacteristic for the two recipient cultivars S29 and Dm2. A larger number of long trichomes was formed in the genetic background of S29, which carry the bread wheat gene Hl1 and Hl3 for leaf pubescence, than in Dm2. Development of substitution and isogenic lines with the fragment of introgression carrying the gene Hltt will allow determining function and assessing the adaptive significance of the gene more precisely.

Assessment of Quantitative Traits of Rajma Bean (Phaseoulus vulgaris L.) Accessions for Yield and Yield Attributing Traits in Multi-Environments of Nepal

Rajma (Phaseolus vulgaris L) known as the common bean, French bean, kidney bean, bush bean, and pole bean is the most important grain legume of Nepal which covers about 10,529 ha areas along with the productivity of 1477kgha-1. Generally it is grown during summer in mid/high hills and during winter (post rainy) season interai/inner terai in rice and maize based eco-system. Now Rajma bean is being popular as the cash crop in the province 3, 5 and 6 because of producing organic products and tastier quality. Multi-environment trials was carried out at Nepalgunj, Parwanipur, Itahari and Surkhet during the winter season of 2014-2017 comprised of 10 diverse Rajma genotypes in Randomized Complete Block Design with three replications in order to evaluate the quantitative variation with respect to yield and yield contributing traits. The combined analysis of variance showed that the highly significant differences among the genotypes and locations in the traits like days to flowering, days to maturity, plant height, hundred seed weight and grain yield. However; there was not any GxE interaction effect found in days to flowering, days to maturity and grain yield. Mean yield performances showed that the genotype PDR-14 (2341kgha-1) produced the highest yield followed by Utkarsh (2332kgha-1) and Arun-2 (2021kgha-1). In conclusion, PDR-14 gave 9-56% higher yield among the genotypes and its stability analysis test also indicated that PDR-14 was found a highly stable across the environments and over the years. Variegated red kidney shape seed, white flowers along with dwarf and glabrous leaf pubescence is the DUS trait of the PDR-14 and recommended for terai/inner terai to high hills.

Plant structural diversity alters sediment retention on and underneath herbaceous vegetation in a flume experiment

Sediment retention is a key ecosystem function provided by floodplains to filter sediments and nutrients from the river water during floods. Floodplain vegetation is an important driver of fine sediment retention. We aim to understand which structural properties of the vegetation are most important for capturing sediments. In a hydraulic flume experiment, we investigated this by disentangling sedimentation on and underneath 96 vegetation patches (40 cm x 60 cm). We planted two grass and two herb species in each patch and conducted a full-factorial manipulation of 1) vegetation density, 2) vegetation height, 3) structural diversity (small-tall vs tall-tall species combinations) and 4) leaf pubescence (based on trait information). We inundated the vegetation patches for 21 h in a flume with silt- and clay-rich water and subsequently measured the amount of accumulated sediment on the vegetation and on a fleece as ground underneath it. We quantified the sediment by washing it off the biomass and off the fleece, drying the sediment and weighting it. Our results showed that all manipulated vegetation properties combined (vegetation density and height, and the interaction of structural diversity and leaf pubescence) explained sedimentation on the vegetation (total R2 = 0.34). The sedimentation underneath the vegetation was explained by the structural diversity and the leaf pubescence (total R2 = 0.11). We further found that vegetation biomass positively affected the sedimentation on and underneath the vegetation. These findings are crucial for floodplain management strategies with the aim to increase sediment retention. Based on our findings, we can identify management strategies and target plant communities that are able to maximize a floodplain’s ability to capture sediments.

Particle size, leaf pubescence and condition of humidity at leaf surfaces are key factors determining the retention of volcanic ash on crop foliage.

<p>Volcanic ashfall negatively affects crops, causing major economic losses and jeopardising the livelihood of farmers in developing countries where agriculture is at volcanic risk. Ash on plant foliage reduces the amount of incident light, thereby limiting photosynthesis and plant yield. An excessive ash load may also result in mechanical plant damages, such as defoliation and breakage of the stem and twigs. Characterising crop vulnerability to ashfall is critical to conduct a comprehensive volcanic risk analysis. This is normally done by describing the relationship between the ash deposit thickness and the corresponding reduction in crop yield, i.e. a fragility function. However, ash depth measured on the ground surface is a crude proxy of ash retention on plant foliage as this metrics neglects other factors, such as ash particle size, leaf pubescence and condition of humidity at leaf surfaces, which are likely to influence the amount of ash that stays on leaves.</p><p>Here we report the results of greenhouse experiments in which we measured the percentage of leaf surface area covered by ash particles for one hairy leaf plant (tomato, Solanum lycopersicum L.) and one hairless leaf plant (chilli pepper, Capsicum annuum L.) exposed to simulated ashfalls. We tested six particle size ranges (≤ 90, 90-125, 125-250, 250-500, 500-1000, 1000-2000 µm) and two conditions of humidity at leaf surfaces, i.e. dry and wet. Each treatment consisted of 15 replicates. The tomato and chilli pepper plants exposed to ash were at the seven- and eight-leaf stage, respectively. An ash load of ~570 g m<sup>-2 </sup>was applied to each plant using a homemade ashfall simulator. We estimated the leaf surface area covered by ash from pictures taken before and immediately after the simulated ashfall. The ImageJ software was used for image processing and analysis.</p><p>Our results show that leaf coverage by ash increases with decreasing particle size. Exposure of tomato and chilli pepper to ash ≤ 90 μm always led to ~90% coverage of the leaf surface area. For coarser particles sizes (i.e. between 125 and 500 µm) and dry condition at leaf surfaces, a significantly higher percentage (on average 29 and 16%) of the leaf surface area was covered by ash in the case of tomato compared to chilli pepper, highlighting the influence of leaf pubescence on ash retention. In addition, for particle sizes between 90 and 500 µm, wetting of the leaf surfaces prior to ashfall enhanced the ash cover by 19 ± 5% and 34 ± 11% for tomato and chilli pepper, respectively.</p><p>These findings highlight that ash deposit thickness alone cannot describe the hazard intensity accurately. A thin deposit of fine ash (≤ 90 µm) will likely cover the entire leaf surface area, thereby eliciting a disproportionate effect on plant foliage compared to a thicker but coarser deposit. Similarly, for a same ash depth, leaf pubescence and humid conditions at the leaf surfaces will enhance ash retention, thereby increasing the likelihood of damage. Our study will contribute to improve the reliability of crop fragility functions used in volcanic risk assessment.</p>