Genetic Variability and Correlation Studies for Pre-harvest Sprouting Tolerance and Associated Traits in Soybean [Glycine max L. Merrill.]

Evaluation of a set of 65 diverse genotypes of soybean was carried out for their pre-harvest sprouting (PHS) tolerance in a field study during kharif 2019. Percentage of pods ruptured by sprouting seed (PPR) was used as a measure of pre-harvest sprouting tolerance. It ranged from 0-5.8% among the genotypes. High estimates of genotypic (GCV) and phenotypic coefficients of variation (PCV) were recorded for the percentage of pods ruptured by sprouting seed (PPR) indicating the presence of wider variability over which selection can be effective. High heritability coupled with high genetic advance as percent mean was recorded for number of pods ruptured by sprouting seed per plant and PPR. The phenotypic character association revealed a significant negative correlation of PPR with pod wall thickness, number of pods per plant, and number of clusters per plant. Path coefficient analysis revealed number of pods per plant, plant height, and pod wall thickness have a negative influence on pre-harvest sprouting.

Study of Alcoholic Extract of Acacia Farnesiana (L.) Willd Pods

Identification of bioactive compound from alcoholic extract of Acacia farnesiana leguminosae pods by using preliminary phytochemical test or thin layer chromatography and the quantification of total phenolic content by folin-ciocalteu reagent method. shade dried grounded powder of Acacia farnesiana pods was successively extracted with petroleum ether, chloroform and alcohol in soxhlet apparatus, alcoholic compound obtained in more amount as compare to other two extract so alcoholic extract was used for identification of bioactive compound. The alcoholic extract of leguminosae pods indicates the presence of major bioactive compound. Analysis of the alcoholic extract by TLC have identified naringenin from extract, and the total phenolic content in alcoholic extract was found to be 22%(w/w). Therefore the present study deals with qualitative analysis of alcoholic extract of legumae pericarp (pod wall) of Acacia farnesiana L. In which we analyze various phytochemical which are useful for contoling various diseases TLC method used for identification of the content of naringenin from active extract of Acacia farnesiana pods. It is concluded that, legume pods contain maximum phytoconstituents or phenolic content.

Identification of redgram resistant genotypes and morphological bases of resistance to pod fly, Melanagromyza obtusa (Malloch)

Screening of 49 redgram genotypes conducted to identify pod fly resistant genotypes and morphological basis of resistance to pod fly revealed consistently resistance reaction of ICP 8864 (mean PSI 3.0) and VRG–59-1(mean PSI 3.3) to redgram pod fly. Pod length of various redgram germplasm ranged between 3.55 and 4.84 cm. Pod width ranged from 0.64 to 1.28 cm. Pod wall thickness ranged from 0.21 to 0.43 mm. Trichome density ranged between 302 and 375 per 9 mm2. Redgram pod width was the important morphological factor that influenced the redgram pod fly seed damage to a tune of 34.2 per cent. Pod length and width were positively correlated with the redgram pod fly seed damage while pod wall thickness and trichome density were negatively correlated. However, relationship between pod width and seed damage only was found to be significantly positive and rest of the morphological factors were not significant.

Ultrastructural and Photosynthetic Responses of Pod Walls in Alfalfa to Drought Stress

Increasing photosynthetic ability as a whole is essential for acquiring higher crop yields. Nonleaf green organs (NLGOs) make important contributions to photosynthate formation, especially under stress conditions. However, there is little information on the pod wall in legume forage related to seed development and yield. This experiment is designed for alfalfa (Medicago sativa) under drought stress to explore the photosynthetic responses of pod walls after 5, 10, 15, and 20 days of pollination (DAP5, DAP10, DAP15, and DAP20) based on ultrastructural, physiological and proteomic analyses. Stomata were evidently observed on the outer epidermis of the pod wall. Chloroplasts had intact structures arranged alongside the cell wall, which on DAP5 were already capable of producing photosynthate. The pod wall at the late stage (DAP20) still had photosynthetic ability under well-watered (WW) treatments, while under water-stress (WS), the structure of the chloroplast membrane was damaged and the grana lamella of thylakoids were blurry. The chlorophyll a and chlorophyll b concentrations both decreased with the development of pod walls, and drought stress impeded the synthesis of photosynthetic pigments. Although the activity of ribulose-1,5-bisphosphate carboxylase (RuBisCo) decreased in the pod wall under drought stress, the activity of phosphoenolpyruvate carboxylase (PEPC) increased higher than that of RuBisCo. The proteomic analysis showed that the absorption of light is limited due to the suppression of the synthesis of chlorophyll a/b binding proteins by drought stress. Moreover, proteins involved in photosystem I and photosystem II were downregulated under WW compared with WS. Although the expression of some proteins participating in the regeneration period of RuBisCo was suppressed in the pod wall subjected to drought stress, the synthesis of PEPC was induced. In addition, some proteins, which were involved in the reduction period of RuBisCo, carbohydrate metabolism, and energy metabolism, and related to resistance, including chitinase, heat shock protein 81-2 (Hsp81-2), and lipoxygenases (LOXs), were highly expressed for the protective response to drought stress. It could be suggested that the pod wall in alfalfa is capable of operating photosynthesis and reducing the photosynthetic loss from drought stress through the promotion of the C4 pathway, ATP synthesis, and resistance ability.

Narrowing Down a Major QTL Region Conferring Pod Fiber Contents in Yardlong Bean (Vigna unguiculata), a Vegetable Cowpea

Yardlong bean (Vigna unguiculata (L.) Walp. ssp. sesquipedalis), a subgroup of cowpea, is an important vegetable legume crop of Asia where its young pods are consumed in both fresh and cooked forms. Pod fiber contents (cellulose, hemicellulose and lignin) correlates with pod tenderness (softness/hardness) and pod shattering. In a previous study using populations derived from crosses between yardlong bean and wild cowpea (V. unguiculata ssp. unguiculata var. spontanea), three major quantitative trait loci (QTLs), qCel7.1, qHem7.1 and qLig7.1, controlling these fibers were identified on linkage group 7 (cowpea chromosome 5) and are co-located with QTLs for pod tenderness and pod shattering. The objective of this study was to identify candidate gene(s) controlling the pod fiber contents. Fine mapping for qCel7.1, qHem7.1 and qLig7.1 was conducted using F2 and F2:3 populations of 309 and 334 individuals, respectively, from the same cross combination. New DNA markers were developed from cowpea reference genome sequence and used for fine mapping. A QTL analysis showed that in most cases, each pod fiber content was controlled by one major and one minor QTLs on the LG7. The major QTLs for cellulose, hemicellulose and lignin in pod were always mapped to the same regions or close to each other. In addition, a major QTL for pod shattering was also located in the region. Although there were several annotated genes relating to pod fiber contents in the region, two genes including Vigun05g266600 (VuBGLU12) encoding a beta glucosidase and Vigun05g273500 (VuMYB26b) encoding a transcription factor MYB26 were identified as candidate genes for the pod fiber contents and pod shattering. Function(s) of these genes in relation to pod wall fiber biosynthesis and pod shattering was discussed.

Physiological and molecular aspects of pod shattering resistance in crops

Pod shattering resistance is a trait acquired by crops in the process of evolution. Manipulation of physiological and molecular processes is fundamental for the improvement of shattering resistance in crops. In this review we discuss several enzymes, key hormones and their possible roles or relationships involved in pod shattering, and highlight responsible genes, quantitative traits loci (QTLs) and their implications for increased pod shattering resistance. Cell wall degrading enzymes, particularly β-glucanases and endopolygalacturonases play an important role in the process of pod dehiscence. It is not clear how and to what extent a specific hormone regulates the dehiscence zone differentiation and the dehiscence process is not clear. Resistance to shattering is highly heritable and is not controlled by a single gene. Several QTLs associated to dehiscence have been identified in crops, while the underlying genetic functions of these QTLs deserve further investigation. Further physiological analyses of the pod wall will help to understand better the pod dehiscence.