Effect of soil solarization on true potato (Solanum tuberosum L.) seed germination, seedling growth, weed population and tuber yield

Summary True potato seed of 17 progenies were evaluated during 2002-03 and 2003-04 crop seasons for 12 characters related to seed germination, seedling growth and weed population in nursery beds and tuber yield of transplanted seedlings under non-solarized field conditions. Solarization was found to have beneficial effect on seed germination, seedling growth and yield of transplanted seedlings. Total weeds and major annual weedCornopus didymus were reduced to a great extent due to solarization. However solarization had no effect onCyperus rotundus. Progenies also showed significant differences among themselves for the various characters studied. The progeny x solarization interaction was also significant for all the characters. Yield increase in present study shows that the approach involving raising of seedlings in solarized nursery beds and subsequent transfer of seedlings to non-solarized field would be cost-effective and profitable for raising true seed crop of potato.     

Ebola virus – epidemiology,diagnosis, and control: threat to humans,lessons learnt,and preparedness plans – an update on its 40 year's journey

Ebola virus (EBOV) is an extremely contagious pathogen and causes lethal hemorrhagic fever disease in man and animals. The recently occurred Ebola virus disease (EVD) outbreaks in the West African countries have categorized it as an international health concern. For the virus maintenance and transmission, the non-human primates and reservoir hosts like fruit bats have played a vital role. For curbing the disease timely, we need effective therapeutics/prophylactics, however, in the absence of any approved vaccine, timely diagnosis and monitoring of EBOV remains of utmost importance. The technologically advanced vaccines like a viral-vectored vaccine, DNA vaccine and virus-like particles are underway for testing against EBOV. In the absence of any effective control measure, the adaptation of high standards of biosecurity measures, strict sanitary and hygienic practices, strengthening of surveillance and monitoring systems, imposing appropriate quarantine checks and vigilance on trade, transport, and movement of visitors from EVD endemic countries remains the answer of choice for tackling the EBOV spread. Herein, we converse with the current scenario of EBOV giving due emphasis on animal and veterinary perspectives along with advances in diagnosis and control strategies to be adopted, lessons learned from the recent outbreaks and the global preparedness plans. To retrieve the evolutionary information, we have analyzed a total of 56 genome sequences of various EBOV species submitted between 1976 and 2016 in public databases.     

Molecular breeding for resistance to black rot [<Emphasis Type="Italic">Xanthomonas campestris</Emphasis> pv. <Emphasis Type="Italic">campestris</Emphasis> (Pammel) Dowson] in <Emphasis Type="Italic">Brassicas</Emphasis>: recent advances

The Brassicas are affected by several diseases, of which black rot, Xanthomonas campestris pv. campestris (Pam.) Dowson (Xcc), is one of the most widespread and devastating worldwide. The black rot bacteria causes systemic infection in the susceptible plants and penetrate the plants through the hydathodes or wounds. Typical disease symptoms are ‘V’ shaped necrotic lesions appearing from the leaf margins with blackened veins. Periodic outbreaks of the black rot pathogen have occurred worldwide, especially in the continental regions, where high temperatures and humidity favor the incidence of disease occurrence causing huge yield loss. The challenge to control the losses in vegetable brassicas production is made more difficult by the adverse climatic changes and evolution of new pathogenic races. The development of black rot resistant hybrids/varieties is the most reliable long term practical solution for effective disease control. Identification of new resistant genetic resources, tightly linked markers with resistance loci and QTL mapping would facilitate the breeding programme for black rot resistance. Information regarding genetics of resistance and mapping of resistance genes/QTLs will accelerate the marker assisted resistance breeding in brassica crops against Xcc. In future we need to identify the race specific candidate genes for and their validation through transgenics and gene expression. Moreover, it is imperative to identify functional markers for resistance genes through identification of R gene families and their relationship with resistance expression. This comprehensive review will help the researchers working in this area to understand the dynamics of black resistance breeding and to formulate future breeding strategies.     

Cytoplasmic male sterile and doubled haploid lines with desirable combining ability enhances the concentration of important antioxidant attributes in <Emphasis Type="Italic">Brassica oleracea</Emphasis>

The Brassica vegetable crops are rich source of important antioxidant compounds having anticancer and health promoting properties. Development of F₁ hybrids with better nutritional traits is one of the main breeding objectives in different vegetable crops. Our study is the first report of determining heterotic combinations utilizing cytoplasmic male sterile (CMS) and doubled haploid (DH) inbred lines for antioxidant compounds in snowball cauliflower. Twenty genetically diverse Ogura CMS lines of cauliflower and six DH male fertile inbred lines were crossed to develop 120 F₁ hybrids in line?×?tester mating design. The resulting 120 test cross progenies along with 26 parents and 4 standard checks were evaluated in 10?×?15 alpha lattice design with three replications during next cropping season. The CMS lines Ogu33-1A, Ogu122-5A and Ogu119-1A were good general combiner and CMS line Ogu118-6A was poor general combiner for majority of traits. Most of the heterotic hybrids were associated with high positive SCA effects. The proportions of σ²A/D and \(\upsigma^{2}_{\text{gca}} /\upsigma^{2}_{\text{sca}}\) ratios were less than unity in all the cases indicating preponderance of non-additive gene action in the genetic control of all the traits. Highest number of heterotic hybrids with SCA effects in desired positive direction was recorded for ascorbic acid content and phenolic content followed by total carotenoid content. The F₁ hybrids with better combining ability and better per se performance could be useful in accumulation of favourable allele for higher concentration of important anti-oxidant compounds.     

Genetic variation for tolerance to post-emergence herbicide,imazethapyr in lentil (Lens culinaris Medik.)

Weeds pose a serious constraint to lentil production. Identification and deployment of post-emergence herbicide tolerance in improved varieties can help reduce the production cost and increase the productivity and area under lentil cultivation. Imazethapyr, a post-emergence herbicide was tested on 180 lentil genotypes for two consecutive years. Significant variation among the genotypes was observed for tolerance to imazethapyr. On a 1–5 scale, 12 genotypes were found tolerant, 46 moderately tolerant, 112 sensitive and 10 highly sensitive during the first season, and 11 genotypes were found tolerant, 51 moderately tolerant, 110 sensitive and 8 highly sensitive during the second season. Based on the first year’s result, 30 genotypes, representing tolerant, moderately tolerant, sensitive and highly sensitive reactions, were evaluated to determine the effect of herbicide on morpho-physiological and yield traits. The adverse effect of imazethapyr was significant on growth and yield attributes of lentils. Five genotypes namely LL699, LL1397, IPL406, EC78452 and LL1203 demonstrated tolerance to imazethapyr with limited phytotoxic effect on various morpho-physiological traits. These genotypes showed less reduction (<19%) for seed yield in imazethapyr treated plots as compared to control. These genotypes offer scope for developing post-emergence herbicide tolerant cultivars in lentil.     

逆境胁迫下的农业管理中土壤-植物-微生物相互作用研究进展

The expected rise in temperature and decreased precipitation owing to climate change and unabated anthropogenic activities add complexity and uncertainty to agro-industry.The impact of soil nutrient imbalance,mismanaged use of chemicals,high temperature,flood or drought,soil salinity,and heavy metal pollutions,with regard to food security,is increasingly being explored worldwide.This review describes the role of soil-plant-microbe interactions along with organic manure in solving stressed agriculture problems.Beneficial microbes associated with plants are known to stimulate plant growth and enhance plant resistance to biotic (diseases) and abiotic (salinity,drought,pollutions,etc.) stresses.The plant growth-promoting rhizobacteria (PGPR) and mycorrhizae,a key component of soil microbiota,could play vital roles in the maintenance of plant fitness and soil health under stressed environments.The application of organic manure as a soil conditioner to stressed soils along with suitable microbial strains could further enhance the plant-microbe associations and increase the crop yield.A combination of plant,stress-tolerant microbe,and organic amendment represents the tripartite association to offer a favourable environment to the proliferation of beneficial rhizosphere microbes that in turn enhance the plant growth performance in disturbed agro-ecosystem.Agriculture land use patterns with the proper exploitation of plant-microbe associations,with compatible beneficial microbial agents,could be one of the most effective strategies in the management of the concerned agriculture lands owing to climate change resilience.However,the association of such microbes with plants for stressed agriculture management still needs to be explored in greater depth.     

Silvopastoral systems improve carbon stocks at livestock ranches in Tabasco,Mexico

Silvopastoral systems have great potential for storing carbon because of carbon assimilation in tree woody biomass, carbon input through litterfall and below-ground carbon turnover. In this study, we quantified and compared the carbon stocks at livestock ranches in Tabasco, Mexico, containing either scattered trees in grazing pastures (STP) or grass monocultures. Sampling plots were randomly established at each ranch where the above- and below-ground carbon stocks, carbon input from litterfall, grass production and arboreal biomass growth were measured. We found that silvopastoral systems stored an average of 257.45 Mg ha⁻¹ of soil organic carbon (SOC) compared to 119.17 Mg SOC ha⁻¹ at grass monoculture ranches (to 30 cm depth); silvopastoral systems also stored 44.64 Mg C ha⁻¹ in wood biomass; and, grass monocultures had greater cumulative grass biomass production. Overall, it is concluded that livestock ranches in Tabasco, Mexico, with scattered trees in grazing pastures stored 58.8% more carbon than those grass monocultures, with carbon stocks of 327.01 Mg C ha⁻¹and 134.47 Mg C ha⁻¹, respectively. The results are useful for land management decision making for sustainable livestock systems framed in the Sustainable Development Goals (SDGs).