Study of interspecific SSR polymorphism among 14 species from Triticum-Aegilops group

In the present study, using in-gel hybridization and PCR based approaches, interspecific SSR polymorphism was studied among 14 species of Triticum-Aegilops group. The material represented seven different genomes and three ploidy levels (2x,4x,6x). In-gel hybridization involved 13 probe-enzyme combinations (four SSR oligonucleotide probes in combination with 2-4 enzymes) and resolved 5 to 20 bands (0.40kb to > 23kb) in each of the 14 individual species. This suggested ubiquitous distribution and interspecific polymorphism of SSRs among different species of Triticum-Aegilops group. The available polymorphism also proved helpful in discriminating not only the species with different ploidy levels and possessing different genomes, but also those possessing similar or very closely related genomes. The amplification of SSR loci using 15 primer pairs derived from hexaploid wheat was also carried out in all the 14 species. The primer pairs, each amplified SSR loci not only in species containing A, B and D genomes, but also in 2 to 10 of the remaining species that contained other genomes. This suggested that wheat SSRS might have been derived from the corresponding SSRs in an ancestral genome and are conserved across a number of species in the Triticum-Aegilops group. Also, two pairs of SSRs (one consisting of WMC243 and WMC415 and the other consisting of WMC35 and WMC404) each discriminated all the 14 species examined during the present study. Therefore, one can infer from the present study that SSR primers can be used in studies on DNA polymorphism, genetic diversity, gene mapping and synteny conservation across different species of Triticum-Aegilops group

Dynamics of Indian fresh mango export

Increasing integration of global markets after WTO has brought several changes in fresh mango export. The sustainability of exporters' income depends on acceptance of consignments by the importing countries who have established legally vetted system of safe import of food commodities. To adjust to these changes, the Indian system of export controls faltered to meet the standards of overseas markets. Adherence to safe export norms is sine qua non to have credible sustainable export. Visualizing the need to discern and quantify the direction of fresh mango export, time series data spanning from 1990-2012 was analysed. From the analysis, it can be concluded that domestic supply of mango is mainly driven by expansion of area rather than productivity. High standards of SPS measures of importing countries raised cost of compliance of safe export norms for which Indian exporters faced problems to adjust to these standards. These challenges need to overcome through generation of research based scientific knowledge for structuring food safety norms and policy alignment according to the changing global regulations. Policy options for streamlining diversified export are to encourage food testing laboratories to get accreditation from international agencies setting up world class food testing and inception infrastructure particularly in clusters with significant presence of exporters to encourage importing countries to set up office for certification of export consignments, and to strengthen prerequisite physical resources for safe export of fresh mango

Genetic analysis and molecular mapping of a new fertility restorer gene Rf8 for Triticum timopheevi cytoplasm in wheat (Triticum aestivum L.) using SSR markers

A study on mode of inheritance and mapping of fertility restorer (Rf) gene(s) using simple sequence repeat (SSR) markers was conducted in a cross of male sterile line 2041A having Triticum timopheevi cytoplasm and a restorer line PWR4099 of common wheat (Triticum aestivum L.). The F1 hybrid was completely fertile indicating that fertility restoration is a dominant trait. Based on the pollen fertility and seed set of bagged spikes in F2 generation, the individual plants were classified into fertile and sterile groups. Out of 120 F2 plants, 97 were fertile and 23 sterile (based on pollen fertility) while 98 plants set ≥5 seeds/spike and 22 produced ≤4 or no seed. The observed frequency fits well into Mendelian ratio of 3 fertile: 1 sterile with χ2 value of 2.84 for pollen fertility and 2.17 for seed setting indicating that the fertility restoration is governed by a single dominant gene in PWR4099. The three linked SSR markers, Xwmc503, Xgwm296 and Xwmc112 located on the chromosome 2DS were placed at a distance of 3.3, 5.8 and 6.7 cM, respectively, from the Rf gene. Since, no known Rf gene is located on the chromosome arm 2DS, the Rf gene in PWR4099 is a new gene and proposed as Rf8. The closest SSR marker, Xwmc503, linked to the Rf8 was validated in a set of Rf, maintainer and cytoplasmic male sterile lines. The closely linked SSR marker Xwmc503 may be used in marker-assisted backcross breeding facilitating the transfer of fertility restoration gene Rf8 into elite backgrounds with ease

БАКТЕРІАЛЬНИЙ ЕНДОМЕТРИТ КОРІВ ТА СУЧАСНИЙ СТАН ЙОГО ЕТІОТРОПНОЇ ТЕРАПІЇ

In the article a literature review related to the etiology, epizootology, pathogenesis, clinical symptoms of endometritis in cows and modern means of its etiotropic therapy is provided. Postpartum endometritis is considered one of the most common diseases in cows, causing great economic losses to dairy operators, due to the increase in the number of unfertilized cows after repeated artificial insemination, the increase of the service period and the percentage of culled cows, treatment costs, decrease in milk yield, etc. The main role in the etiology of endometritis in cows in the postpartum period is assigned to bacterial opportunistic microflora. In the etiology of endometritis, the basic role is played by Staphylococcus spp., Streptococcus spp. and Escherichia coli. Other bacteria can cause endometritis in cows, such as: Actinomyces pyogenes, Fusobacterium necrophorum, Proteus mirabilis, Proteus vulgaris, Pseudomonas aeruginosa, Prevotella spp., Bacteroides spp. In many cases, acute postpartum endometritis in cows is caused by the association of microorganisms, especially Escherichia coli with streptococci and staphylococci. Microorganisms penetrate the mucous membrane of the uterus, their toxins and enzymes destroy nerve endings and capillaries, what leads to a reaction in the form of an inflammatory process, what is localized mainly in the surface layers of the endometrium and in the inter-glandular connective tissue. The development of endometritis depends on the immune response of the cow, as well as on the type and number of bacteria that colonize the endometrium. According to the kind of the inflammatory process, endometritis in cows are classified into: purulent; serous; catarrhal; serous-catarrhal; fibrinous; catarrhal-purulent. According to the passing of the disease, endometritis are acute, subacute, less often - chronic. Diagnosis of endometritis includes collection of anamnestic data, general clinical exploring of the animal and special gynecological (vaginal and rectal) testing. The basis of the treatment of endometritis in cows is etiotropic therapy, what involves by the use of antimicrobial drugs that affect the cause of the disease, and is used to stop the reproduction of opportunistic microflora in the uterine cavity and normalize the microbiocenosis. For the etiotropic therapy of endometritis in cows, drugs for intrauterine administration and drugs for systemic treatment in the form of a solution or suspension for injections are used.У статті надано літературний огляд, що стосується етіології, епізоотології, патогенезу, клінічної симптоматики ендометриту в корів та сучасних засобів його етіотропної терапії. Післяродовий ендометрит вважається однією з найпоширеніших захворювань у корів, що наносить великі економічні збитки для операторів галузі молочного скотарства, пов’язані зі зростанням кількості незапліднених корів після багаторазового штучного осіменіння, збільшенням сервіс-періоду та відсотка вибракуваних корів, витратами на лікування, зниженням надоїв тощо. Основну роль в етіології ендометриту корів у післяпологовий період відводять бактеріальній умовно-патогенній мікрофлорі. В етіології бактеріального ендометриту головну роль відіграють Staphylococcus spp., Streptococcus spp. та Escherichia coli. Викликати ендометрит у корів можуть й інші бактерії, такі як: Actinomyces pyogenes, Fusobacterium necrophorum, Proteus mirabilis, Proteus vulgaris, Pseudomonas aeruginosa, Prevotella spp., Bacteroides spp. У багатьох випадках гострий післяродовий ендометрит в корів викликається асоціації мікроорганізмів, особливо Escherichia coli із streptococci і staphylococci. Мікроорганізми проникають в слизову оболонку матки, а їх токсини і ферменти руйнують нервові закінчення і капіляри, що призводить до реакції у відповідь у вигляді запального процесу, який локалізується переважно в поверхневих шарах ендометрію і в міжзалозистій сполучній тканині. Розвиток ендометриту залежить від імунної відповіді корови, а також від виду і кількості бактерій, яка колонізує ендометрій. За характером запального процесу ендометрити у корів класифікують на: гнійний, серозний, катаральний, серозно-катаральний, фібринозний, катарально-гнійний. За перебігом хвороби ендометрити бувають гострі, підгострі, рідше – хронічні. Діагностика ендометриту включає збір анамнестичних даних, загальний клінічний огляд тварини та спеціальне гінекологічне (вагінальне та ректальне) обстеження. Основою лікування ендометриту корів є етіотропна терапія, що передбачає застосування антимікробних препаратів, які впливають на причину хвороби, і використовується для зупинки розмноження у порожнині матки умовно-патогенної мікрофлори та нормалізації мікробіоценозу. Для етіотропної терапії ендометритів у корів в основному використовують препарати для внутрішньоматкового введення та препарати для системного лікування у формі розчину чи суспензії для ін’єкцій

Development of SSR markers and construction of a linkage map in jute

Jute is an important natural fibre crop, which is only second to cotton in its importance at the global level. It is mostly grown in Indian subcontinent and has been recently used for the development of genomics resources. We recently initiated a programme to develop simple sequence repeat markers and reported a set of 2469 SSR that were developed using four SSR-enriched libraries (Mir et al. 2009). In this communication, we report an additional set of 607 novel SSR in 393 SSR containing sequences. However, primers could be designed for only 417 potentially useful SSR. Polymorphism survey was carried out for 374 primer pairs using two parental genotypes (JRO 524 and PPO4) of a mapping population developed for fibre fineness; only 66 SSR were polymorphic. Owing to a low level of polymorphism between the parental genotypes and a high degree of segregation distortion in recombinant inbred lines, genotypic data of only 53 polymorphic SSR on the mapping population consisting of 120 RIL could be used for the construction of a linkage map; 36 SSR loci were mapped on six linkage groups that covered a total genetic distance of 784.3 cM. Hopefully, this map will be enriched with more SSR loci in future and will prove useful for identification of quantitative trait loci/genes for molecular breeding involving improvement of fibre fineness and other related traits in jute

Genetic dissection of grain weight in bread wheat through quantitative trait locus interval and association mapping

Genetic dissection of grain weight in bread wheat was undertaken through both genome-wide quantitative trait locus (QTL) interval mapping and association mapping. QTL interval mapping involved preparation of a framework linkage map consisting of 294 loci {194 simple sequence repeats (SSRs), 86 amplified fragment length polymorphisms (AFLPs) and 14 selective amplifications of microsatellite polymorphic loci (SAMPL)} using a bi-parental recombinant inbred line (RIL) mapping population derived from Rye Selection111 × Chinese Spring. Using the genotypic data and phenotypic data on grain weight (GW) of RILs collected over six environments, genome-wide single locus QTL analysis was conducted to identify main effect QTL. This led to identification of as many as ten QTL including four major QTL (three QTL were stable), each contributing >20% phenotypic variation (PV) for GW. The above study was supplemented with association mapping, which allowed identification of 11 new markers in the genomic regions that were not reported earlier to harbour any QTL for GW. It also allowed identification of closely linked markers for six known QTL, and validation of eight QTL reported earlier. The QTL identified through QTL interval mapping and association mapping may prove useful in marker-assisted selection (MAS) for the development of cultivars with high GW in bread whea

Structural and functional insights into the candidate genes associated with different developmental stages of flag leaf in bread wheat (Triticum aestivum L.)

Grain yield is one of the most important aims for combating the needs of the growing world population. The role of development and nutrient transfer in flag leaf for higher yields at the grain level is well known. It is a great challenge to properly exploit this knowledge because all the processes, starting from the emergence of the flag leaf to the grain filling stages of wheat (Triticum aestivum L.), are very complex biochemical and physiological processes to address. This study was conducted with the primary goal of functionally and structurally annotating the candidate genes associated with different developmental stages of flag leaf in a comprehensive manner using a plethora of in silico tools. Flag leaf-associated genes were analyzed for their structural and functional impacts using a set of bioinformatics tools and algorithms. The results revealed the association of 17 candidate genes with different stages of flag leaf development in wheat crop. Of these 17 candidate genes, the expression analysis results revealed the upregulation of genes such as TaSRT1-5D, TaPNH1-7B, and TaNfl1-2B and the downregulation of genes such as TaNAP1-7B, TaNOL-4D, and TaOsl2-2B can be utilized for the generation of high-yielding wheat varieties. Through MD simulation and other in silico analyses, all these proteins were found to be stable. Based on the outcome of bioinformatics and molecular analysis, the identified candidate genes were found to play principal roles in the flag leaf development process and can be utilized for higher-yield wheat production. Copyright © 2022 Mehla, Kumar, Kapoor, Singh, Sihag, Sagwal, Balyan, Kumar, Ahalawat, Lakra, Singh, Pesic, Djalovic, Mir and Dhankher

Identifying quantitative trait loci for lodging-associated traits in the wheat doubled-haploid population Avalon × Cadenza

Lodging affects grain quality and grain yield in wheat (Triticum aestivum L.) and is difficult to breed for because its sporadic incidence and laborious protocols to measure lodging traits. Thus, developing molecular markers for these traits can increase selection efficiency in breeding programs. The aim of this article is to identify quantitative trait loci (QTL) associated with stem/anchorage strength and leverage traits (lodging traits) in a doubled-haploid population of UK bread wheat Avalon× Cadenza. Field experiments were conducted in the UK during 2012–2013 near High Mowthorpe and during 2013–2014 at Sutton Bonington. Phenotypic and genetic analysis indicated significant genetic variation for all traits. Stem strength (diameter, wall width, and material strength) and leverage (plant height) traits were highly heritable (0.64–0.95), whereas anchorage strength traits (root plate spread and structural rooting depth) and ear number per plant (leverage trait) were less heritable (0.21–0.33). This study identified 18 QTL for lodging traits and grain yield in chromosomes 1D, 2B, 2D, 3A, 3B, 4A, 4D, 5B, and 6B. Two QTL for stem strength on chromosome 1D and 3B explaining 49.6% of the total phenotypic variation (PVE) are estimated to reduce stem lodging risk and shortening the plant height by 12cm. One QTL for root plate spread on chromosome 5B explaining 22.4% of the PVE could increase root lodging resistance