Real-time PCR carried out on DNA extracted from serum or blood sample is not a good method for surveillance of bovine brucellosis

Bovine brucellosis is endemic in many parts of the world including India. The disease diagnosis and surveillance are usually carried out by serological tests, which however have drawbacks. This study was undertaken to evaluate the potential of real-time PCR (RT-PCR) targeting bcsp31 gene for surveillance of bovine brucellosis. A total of 461 samples, which included 408 stored serum and 53 prospective blood samples, were used. It was found that 33 (7.15 %) samples were positive by RT-PCR, whereas 149 (32.32 %) and 132 (28.63 %) were positive by Rose Bengal plate test (RBPT) or standard agglutination test (STAT), respectively. The results of this study suggest that RT-PCR targeting bcsp31 gene carried out on DNA extracted from serum or blood may not be a suitable method for surveillance of brucellosis in bovines.     

Delivering rust resistant wheat to farmers: a step towards increased food security

An important step towards reducing the vulnerability of wheat in Africa and Asia to the Ug99 race of the stem rust pathogen is the substitution of current susceptible varieties with superior resistant varieties. In the 2008?C2009 cropping season both seed multiplication and dissemination of Ug99 resistant varieties were initiated in Afghanistan, Bangladesh, Egypt, Ethiopia, Iran, India, Nepal and Pakistan. Ug99 resistant varieties must occupy about 5% of the area sown to wheat in each country to ensure sufficient seed to displace current popular varieties. Because of the underdeveloped seed industry and small farm sizes in most of these countries, various strategies are being applied for rapid multiplication and dissemination of resistant varieties. Approaches being used include pre-release seed multiplication while candidate resistant lines are being tested in national evaluation trials and farmer participatory selection. Resistant varieties are already released in Afghanistan, Bangladesh, Egypt and Pakistan and more varieties are expected to be released in 2010 in these and other countries. Our results show that some new Ug99 resistant lines have yield superiority over dominant local varieties. Activities and progress in seed multiplication using existing and new Ug99 resistant varieties are discussed.     

QTL Analysis of Late Blight Resistance in a Diploid Potato Family of Solanum spegazzinii × S. chacoense

Several quantitative trait loci (QTL) for resistance to late blight have been reported in diploid potatoes. The diploid wild potato species Solanum chacoense possesses a high degree of horizontal resistance to late blight. In the present study, we report on QTL mapping for late blight resistance in a diploid mapping population of 126 F₁ of Solanum spegazzinii (susceptible) × S. chacoense (resistant). The area under the disease progress curve (AUDPC) values for late blight resistance using the “whole plant in vitro assay” and the “detached leaf assay” on the mapping population displayed quantitative variation. Out of 64 AFLP primer-pairs combinations and SSR markers, a total of 209 significant AFLP loci were placed onto the 12 linkage group of potato covering a total map length of 6548.1 cM. QTL analysis based on the AUDPC dataset of the “whole plant in vitro assay” using the interval-mapping option identified two QTL (LOD?>?2.5) located on linkage groups IX and X, which explained 14.70 and 3.40% variation, respectively. The present study revealed the presence of potential new genetic loci in the diploid potato family contributing to quantitative resistance against late blight.     

Okra production with pine straw mulch

Conventional planted okra in Booneville, Arkansas and Lorman, Mississippi were mulched with loblolly pine straw (Pinus taeda L.) and longleaf pine straw (P. palustris Mill.), respectively, at a rate of 11 t/ha or left bare. At Booneville, plant stand, season yields (18.6 t/ha), pod weight (16.3 g), plant dry weight (2.3 kg), or stem diameter (3.5 cm) were not affected by the loblolly pine mulch. However, mulch application increased pod number (1.22 vs. 1.06×10⁶/ha) and plant height (1.5 vs. 1.6 m), while reducing weed competition (0.05 vs. 0.40 t/ha) and visible plant stress, during periods of soil moisture deficits. Soil temperatures at 5 and 15 cm depth were reduced by mulch until mid-August when plant canopies covered the rows. Seasonal moisture at 30 and 45 cm depths was similar between mulched and bare soils, based upon unreplicated neutron probe measurements. At Lorman, season okra yield (29.8 vs. 24.6 t/ha), number of pods per ha (1.24 vs. 1.07×10⁶) and weed competition were reduced and soil pH lowered 0.56 units by longleaf pine straw mulch. Mulch reduced early season yield at both locations.     

Path-coefficient analysis of anatomical characters affecting peg strength in groundnut

Summary Correlation and path-coefficient analysis for anatomical characters affecting peg strength was carried out in eleven strains of groundnut. Bundle cap length and number of xylem vessels per vascular bundle showed a significant positive correlation with peg strength. Path-coefficient analysis revealed that bundle cap length had the highest direct positive effect on peg strength whereas number of xylem vessels per vascular bundle played only a minor role directly. All the characters positively affected peg strengh in an indirect manner mostly via bundle cap lengh. All other direct effects and such indirect effects where bundle cap length was not involved were found to be unimportant. Thus bundle cap length emerged as a reliable anatomical character which can serve as a selection criterion in breeding cultivars with strong pegs to reduce harvesting losses in groundnut.     

A linkage group for genes governing pod characters in peanut

Summary Inheritance and linkage relationships were studied for six morphological characters in a cross between Arachis monticola Krap. et Rig. and A. hypogaea L. All the characters were found to be governed by single dominant genes. The genes governing leaflet krinkling and peg pigmentation assorted independently while the genes for four pod characters viz. catenate nature, beak, reticulation and thin pericarp showed linkage. A linkage map for these genes was proposed.     

The application of flow cytometry and a thioredoxin‐like nuclear gene for breeding Poa arachnifera x Poa pratensis hybrids

Interspecific hybridization between Poa arachnifera Torr. (Texas bluegrass) and Poa pratensis L. (Kentucky bluegrass) has shown to be a proven method for the development of turf‐type hybrid bluegrass cultivars for the southern United States. Unlike in P. pratensis, the use of DNA markers for molecular characterization and flow cytometry to determine nuclear DNA contents has not been extensively utilized in P. arachnifera. In this study, 2C nuclear DNA content of 19 different genotypes of P. arachnifera (both males and females) was determined to range from 8.02 to 13.24 pg/2C using flow cytometry. The DNA content of the hybrids between P. arachnifera and P. pratensis from two different pedigrees was found to be intermediate between their parents. Furthermore, the utility of the trx (thioredoxin‐like) nuclear gene in the identification of interspecific hybrids between P. arachnifera and P. pratensis was demonstrated using sequence and phylogenetic analyses. A newly discovered 851‐bp trx allele may serve as a useful marker to differentiate P. arachnifera from P. pratensis and provide insights into the evolutionary origin of P. arachnifera.     

SARS-CoV-2 infection in farmed minks,associated zoonotic concerns,and importance of the One Health approach during the ongoing COVID-19 pandemic

The coronavirus disease 2019 (COVID-19) pandemic has now affected over 72.5 million people worldwide, with nearly 1.6 million deaths reported globally as of December 17, 2020. SARS-CoV-2 has been implicated to have originated from bats and pangolins, and its intermediate animal hosts are being investigated. Crossing of the species barrier and exhibition of zoonosis have been reported in SARS-CoV-2 in farm (minks), domesticated (cats and dogs), and wild animals (tigers, puma, and lions). Recently, the rapid spread of SARS-CoV-2 infection was reported in mink farms, which led to the death of a myriad minks. The clinical and pathological findings of SARS-CoV-2 infection and the rapid animal-to-animal transmission in minks are almost similar to the findings observed in patients with COVID-19. Additionally, the rapid virus transmission among minks and the associated mutations resulted in a new mink-associated variant that was identified in both minks and humans, thereby providing evidence of mink-to-human transmission of SARS-CoV-2. The new mink-associated SARS-CoV-2 variant with a possible reduced sensitivity to neutralizing antibodies poses serious risks and is expected to have a direct effect on the diagnostic techniques, therapeutics, and vaccines that are currently under development. This article highlights the current evidence of SARS-CoV-2 infection in farmed minks, and provides an understanding of the pathogenesis of COVID-19 in minks and the associated zoonotic concerns of SARS-CoV-2 transmission from minks to humans with an emphasis on appropriate mitigation measures and on the necessity of adopting the One Health approach during the COVID-19 pandemic.