Search

Maize (Zea mays) is the third major cereal crop in the Indian subcontinent, but the crop yields per hectare of Indian maize cultivars are less than half of the global average due to the impurity of seed lots supplied to farmers. In this study, we discovered high-quality Single Nucleotide Polymorphic markers (SNPs) in two widely cultivated maize hybrids and their parental inbreds. Paired-end double digest restriction site-associated DNA sequencing was used to discover SNPs and a total of 30,764,454 reads with a read length of 151 bp per sample were generated. Genotyping of SNPs for maize hybrids 'MAH 14-5' and 'Hema' revealed a total of 47,812 and 15,815 Genetic Purity Analysis markers, respectively, of which 44,388 and 12,391 were unique with 3,424 being common to both hybrids. Identified SNPs were used to develop primers for Kompetitive Allele-Specific PCR genotyping assays to determine the genetic purity of 10 seed lots and the results were found to correlate with Grow-out-Tests. Thus, the SNPs discovered in this study proved reliable to test the genetic purity of commercial seed lots. Advances in plant molecular breeding tools especially ddRADseq for SNP discovery offer new opportunities to genotype existing cultivars and accelerate the production of genetically pure seeds.

Identification of chilli cultivar is prime importance to ensuring seed quality during seed production, certification and quality control. Fifteen cultivars were subjected to different biochemical tests Viz., phenol test, modified phenol test with FeSO4 and CuSO4, analysis of soluble seed proteins by SDS-PAGE. No single varieties were so distinct in case of phenol colour reaction, while it helped to group the cultivars. Based on modified phenol text with ferrous sulphates 1per cent (FeSO4) and 0.5 per cent copper sulphate (CuSO4) helped in further classification of cultivars. The cultivars Gouribidanur Local and Phule Jyothi showed unique bands at 14 (Rm: 0.624) and 2 (0.191) level of band. All the cultivars were distinct among each other showing SDS-PAGE as efficient method in chilli cultivar identification.

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) incessantly produced as by-products of metabolism play significant roles in seed physiology. ROS (hydroxyl, superoxide radical and hydrogen peroxide) and RNS (nitric oxide, nitric dioxide, nitrous acid and dinitrogen tetroxide) content changes in all phases of seed life cycle that influence seed germination, dormancy and longevity. Recent studies illustrate that ROS and RNS are performing oxidative and nitrosative signaling to induce seed germination within oxidative window level. Besides, ROS/RNS-mediated post-translational modifications (PTM) like carbonylation, S-nitrosylation and nitration are gaining interest in promoting seed germination. Understanding the signalling pathways, cross-talk with plant hormones and their role in promoting seed germination and dormancy alleviation could pave way for hormone engineering that help in crop productivity, particularly under climatic changing conditions. In addition, role of antioxidants and glutathione thiols in protecting from oxidative damage indicate that these compounds can be used for seed viability/quality markers that aid in monitoring of crop establishment. In this review, sources of ROS and RNS, their cross-talk with plant hormones (prospects for hormone engineering), signalling functions pertaining to seed germination, dormancy and deterioration have been illustrated. In addition, seed quality markers under climatic changing conditions for effective monitoring of crop stand establishment and diagnostics development have been elucidated. Financiado para publicación en acceso aberto: Universidade de Vigo/CISUG Saclay Plant Sciences | Ref. ANR-17-EUR-0007

Endophytes are non-disease causing microbes (bacteria and fungi) surviving in living tissues of plants. Their intimate association and possible coevolution with their plant partners have resulted in them contributing to an array of plant growth benefits ranging from enhanced growth and biomass accumulation, tolerance to abiotic and biotic stresses and in nutrient acquisition. The last couple of decades have witnessed a burgeoning literature on the role of endophytes (Class 3 type) in regulating plant growth and development and their adaptation to abiotic and biotic stresses. Though the underlying mechanisms of plant-endophyte interactions are far from clear, several studies have raised the hope of their potential application in agriculture, especially in mitigating abiotic and biotic stresses. The use of endophytes is envisaged as a route to reduce the production cost and burden on the environment by lessening the dependence on breeding for crop improvement and agrochemicals. Unfortunately, save a few well documented examples of their use, a little of these insights has been translated into actual agricultural applications. Here, we reflect on this paucity and elaborate on some of the important bottlenecks that might stand in way of fully realizing the potential that endophytes hold for crop improvement. We stress the need to study various facets of the endophyte-plant association for their gainful application in agriculture.

Identification of donor parents and markers for traits conferring drought tolerance eventually hastens the breeding for drought tolerance in rice. The extent of variation for water stress indicators, physio-morphological and plant production traits were assessed by evaluating 36 rice genotypes under water stress condition. Significant variation was observed for these traits and thirteen drought tolerant and susceptible genotypes were selected and grouped as tolerant and susceptible bulks based on physio-morphological and biochemical characterization. Genomic DNA was isolated from these rice accessions and pooled, respectively into drought tolerant and susceptible bulks. Bulked line analysis was carried to identify microsatellite markers linked to drought tolerance in rice. Out of 200 SSR primers screened RM 1092; RM 129 and RM157B were polymorphic between the bulks and also co-segregated among the individual genotypes constituting the respective bulks. The genomic regions flanked by these markers have been identified to be associated with various drought tolerance traits in rice and can be useful for marker assisted selection for drought resistance improvement in rice. The genotypes identified as drought tolerant can be used us donars in drought improvement breeding programmes. Key words Rice, drought resistance, microsatellite markers, bulk line analysis

An experiment was designed to find out the best suited seed protein fraction for identifying the genetic contaminants in seeds of two cotton hybrids viz., CSHH 198 and CSHH 238 where its morphological and genetic differences are meager. The electrophoretic comparison of albumin, globulin, and prolamin seed protein fractions revealed that both albumin and globulin fractions are able to differentiate the hybrids from its male and female parents. The analysis of seed proteins of two cotton hybrid revealed that, albumin fraction produced six different fingerprints with highest discrimination ability than globulin fraction (three). Due to this, albumin fraction showed the added advantage in assessment of genetic purity of CSHH 198 hybrid seed lot that are contaminated with its own parental (selfed female) seeds as well as CSHH 238 cotton hybrid. In contrast, globulin fraction can only be used for identification of off type contaminations due to its own parental seeds and prolamin was unable to differen...

During the course of our investigation on the selective isolation and in vitro pathogenicity tests of the nematode egg parasite and endoparasitic Catenaria anguillulae and the nematode-trapping fungus Dactylaria brochopaga against Anguina tritici , and Meloidogyne graminicola, the two biocontrol agents were also examined for their capabilities to colonize wheat seed gall and also to reduce the M. graminicola , and A. tritici in wheat ( Triticum aestivum L.). Using seed galls as bait was found effective for isolating the soilborne natural colonizers of seed galls of wheat caused by A. tritici . Seed galls were found severely infested with cellulose decomposers as well as nematode trapping fungi i.e., Fusarium spp ., Verticillium spp., Aspergillus spp., Penicillium spp. Arthrobotrys oligospora , Arthrobotrys superba , Arthrobotrys dactyloides , Arthrobotrys musiformis , D. brochopaga , Monacrosporium eudermatum, Stylopaga hadra, Paecilomyces spp., and C. anguillulae . Co-inoculation of D. brochopaga DBS-105, and C. anguillulae CAS101 significantly reduced the root knot and seed gall in wheat and increased the plant growth parameters including length, and dry weight of root and shoot as well as yield attributing characters like spike length; number of seed per spike, test weight etc. under greenhouse conditions as compared to pathogen challenged plants without any bioagents/chemical nematicide. These bioagents have the potential to enhance production of quality seeds of wheat being free from hazardous pesticides and thus, can further be developed into marketable formulations in order to promote eco-friendly and sustainable means of crop production.

The soil community is an often ignored part of research which links plant biodiversity and ecosystem functioning despite their influence on numerous functions such as decomposition and nutrient cycling. Few consistent patterns have been detected that link plant and soil community composition; however, it has not been studied in details. Arthrobotrys oligospora, a model predacious fungus for nematode trapping, beside biocontrol potential may modulate plant health and increase natural antioxidants in tomato fruit directly or indirectly. In the present study we have investigated the effects of nematode trapping fungus A. oligospora on induction and bioaccumulation of natural antioxidant and defence related biomolecules in tomato plants when challenged with Meloidogyne incognita causing root knot. Endophytic and rhizospheric isolates of A. oligospora were isolated from different parts of India and characterized under controlled laboratory conditions. The study describes the multifarious effects of endophytic and rhizospheric isolates of A. oligospora in green house and field conditions in tomato plants when inoculated individually or in combination. It was found that A. oligospora EAO-147 and RST-101 when applied individually or in combination significantly increased various attributes in plants. Among both the isolates, endophytic A. oligospora EAO-147 was found to be more potential in enhancing the defence related biomolecules, enzymes and exhibited biocontrol potentials against M. incognita. With application of A. oligospora, increase in nutritional quality of ripe tomato fruits (mineral nutrients and natural antioxidant properties) was also demonstrated first time. Results suggest that application of A. oligospora, particularly endophytic, not only helps in control of nematodes but also increase plant growth as well as enhances the nutritional value of tomato fruits. Thus, it proves to be an excellent biocontrol as well as plant growth promoting agent.

In modern agriculture, advance technologies are being deployed for breaking yield barriers and enhancing crop productivity. Devising varied seed enhancement technologies is an important domain assuring uniform field emergence, better crop stand and realisation of higher yield in different crops. Integration of diverse plant extracts, microbial products and biotic agents through bio-priming for managing seed crop targeting against biotic and abiotic stresses has been considered as a unique approach, as it requires lesser amounts of chemicals, enhances efficacy of the seeds, reduces the cost of management and eliminates pollution hazards while causing minimum interference with biological equilibrium. Seed bio-priming is one of the vital seed enhancement tool in management of biotic as well as abiotic stresses and guarantees uniform stand establishment under stress conditions. Therefore, research programmes encompassing identification and genetic manipulations of novel biocontrol agents (fungal and bacterial strains) along with its commercial application needs to be devised.

Summary Identification of rice genotypes is of prime importance to ensure quality seed, which is required for achieving global food demand. Three rice hybrids and their parental lines were identified on the basis of seed colour, seed size and 1000 seed weight, response to different chemicals (Phenol, Modified phenol with Copper sulphate or Ferrous sulphate, NaOH, GA3 and 2,4-D) and electrophoresis of soluble seed proteins (SDS-PAGE). All the genotypes were identified by using key based on seed colour, 1000 seed weight and seed size except for the female lines and their maintainers. No individual chemical test was able to distinguish all the genotypes. However, the combinations of different rapid chemical tests were useful in identification of individual genotypes. While all the cultivars were identified successfully by using electrophoresis of seed protein (SDS-PAGE) and hence it could be used as a powerful tool to identify every genotype in a short period of time.

The present study was based on primary data collected for 100 farmers from Gulbarga district of Karnataka during the agricultural year 2013-14. Tabular and discriminant function analysis was used in the present study. The analysis of data shows that the total cost of cultivation in pigeonpea seed production was around 23 per cent higher than grain production. The variable cost was comparatively higher in seed production (26936 per ha) over grain production (20698 per ha). The gross return was about 32 per cent higher in seed production than grain production and net return from seed production of pigeonpea was 44 per cent higher than grain production. The discriminant analysis indicated that gross return with 55.88 per cent followed by seed (18.52 per cent), human labour (8.35 per cent), manures and fertilizers (7.01per cent), bullock and machine labour (5.99 per cent), plant protection chemicals (4.26 per cent) contributed to discriminate between the seed and grain production of pigeonpea. The net return from pigeonpea seed production was encouraging, therefore the area under seed production may be increased for higher profitability and timely supply of quality seed to the farmers.

Background Reactive oxygen species (ROS) are considered to be detrimental to seed viability. However, recent studies have demonstrated that ROS have key roles in seed germination particularly in the release of seed dormancy and embryogenesis, as well as in protection from pathogens. Scope This review considers the functions of ROS in seed physiology. ROS are present in all cells and at all phases of the seed life cycle. ROS accumulation is important in breaking seed dormancy, and stimulating seed germination and protection from pathogens. However, excessive ROS accumulation can be detrimental. Therefore, knowledge of the mechanisms by which ROS influence seed physiology will provide insights that may not only allow the development of seed quality markers but also help us understand how dormancy can be broken in several recalcitrant species. Conclusions Reactive oxygen species have a dual role in seed physiology. Understanding the relative importance of beneficial and detrimental effects of ROS provides great scope for the improvement and maintenance of seed vigour and quality, factors that may ultimately increase crop yields.

Nine popular rice (Oryza sativa L.) hybrids were evaluated over three years during kharif season 2008- 2010 to assess stability for grain yield and its contributing traits. Analysis of variance of stability revealed highly significant variance due to environment for all seven traits. The variance for genotypic effect was significant for all traits indicating differential response of hybrids over the environments. Estimates of environmental index showed that performance of hybrids over three environments varied and environment E2 exhibited highest favourable impact on grain yield. Only two hybrids, KRH-2 and PRH-10 revealed stability for grain yield. Hybrid ‘KRH-2’ showed stable performance for all seven characters whereas, PRH-10 exhibited stability for six traits viz.; days to 50% flowering, days to maturity, plant height, panicle length, number of filled grains per panicle and seed yield/m2. Based on stability parameters these two hybrids can be considered as stable performers and may be exploited for yield enhancement of rice under varying environmental conditions while their parental lines could be used in breeding programme to develop new cultivars with combination of stable characters.