Evaluation of regulatory influence of four plant growth regulators on the reproductive potential and longevity of melon fruit fly (Bactrocera cucurbitae)

The topical treatment given to freshly emerged (0–1-day-old) male and female adults ofBactrocera cucurbitae (Coquillett), a serious pest of cucurbit crops in tropical countries, with 25, 125, 625 and 3125 ppm concentrations of gibberellic acid (GA₃), indole-3-acetic acid (IAA), kinetin and coumarin showed a significant adverse influence on the reproductive potential of this fruit fly. The assessment for reproductive potential was made on the basis of reduction in fecundity and fertility of laid eggs and measured as sterility in females and shortening of the longevity,i.e. ovipositional phase. The strongest influence was with kinetin, followed closely by coumarin, then GA₃ and lastly with IAA treatments. It was concluded that although these compounds demonstrate their activities differently in plants and might be following a different mode of action in insects, they ultimately influence the reproductive potential of this insect.     

Fecal glucocorticoids and their metabolites as indicators of stress in various mammalian species: a literature review.

Conservation medicine is a discipline in which researchers and conservationists study and respond to the dynamic interplay between animals, humans, and the environment. From a wildlife perspective, animal species are encountering stressors from numerous sources. With the rapidly increasing human population, a corresponding increased demand for food, fuel, and shelter; habitat destruction; and increased competition for natural resources, the health and well-being of wild animal populations is increasingly at risk of disease and endangerment. Scientific data are needed to measure the impact that human encroachment is having on wildlife. Nonbiased biometric data provide a means to measure the amount of stress being imposed on animals from humans, the environment, and other animals. The stress response in animals functions via glucocorticoid metabolism and is regulated by the hypothalamic-pituitary-adrenal axis. Fecal glucocorticoids, in particular, may be an extremely useful biometric test, since sample collection is noninvasive to subjects and, therefore, does not introduce other variables that may alter assay results. For this reason, many researchers and conservationists have begun to use fecal glucocorticoids as a means to measure stress in various animal species. This review article summarizes the literature on many studies in which fecal glucocorticoids and their metabolites have been used to assess stress levels in various mammalian species. Variations between studies are the main focus of this review. Collection methods, storage conditions, shipping procedures, and laboratory techniques utilized by different researchers are discussed.     

Antioxidative Enzymes and Sucrose Synthase Contribute to Cold Stress Tolerance in Chickpea

Chickpea is sensitive to low temperature (<10°C) during its reproductive stage. Low temperature adversely affects the development of pods and seeds. This study was undertaken to investigate the role of sucrose metabolizing enzymes in seed development and potential of antioxidative enzymes in protecting seeds and podwalls from the deleterious effects of cold stress in advanced cold tolerant chickpea breeding lines. Healthy pod set was observed in these tolerant lines in the end of December where as low temperature susceptible PBG-1 did not flower. Two lines ICCV 96029 and ICCV 96030 showed susceptible characters such as reduced flowering, blackened and shrivelled seeds and yellowish pods in comparison to other cold stress tolerant lines due to sudden dip of temperature (<1 °C) during the first week of January. These two lines were, therefore, treated as susceptible checks in comparison to other tolerant lines. A significantly higher activity and specific activity of sucrose synthase was observed in seeds of most of the cold tolerant lines in comparison with ICCV 96029 and ICCV 96030, thereby providing sugars as well as sugar nucleotides for their growth and starch synthesis during unfavourable low temperature. The developing seeds and podwalls of tolerant genotypes had higher activities of antioxidant enzymes, i.e. catalase, ascorbate peroxidase and glutahione reductase in comparison with ICCV 96029 and ICCV 96030. It appears that the higher activities of antioxidant enzymes in podwall protect the developing seeds from cold stress.     

Small dams need consideration in riverscape conservation assessments

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Biology and chemistry of Ginkgo biloba

Ginkgo biloba has been existing on earth since 200 million years and is considered as a "living fossil". It is among the most sold medicinal plants in the world. A number of secondary metabolites representing terpenoids, polyphenols, allyl phenols, organic acids, carbohydrates, fatty acids and lipids, inorganic salts and amino acids have been isolated from the plant. However, the main bioactive constituents are terpene trilactones and flavonoid glycosides which are considered responsible for the pharmacological activities of its standardized leaf extract. Scattered information is available on the extraction and analysis of these pharmacologically important constituents which have been compiled in the present review.     

Reinventing heterosis phenomenon through deployment of alien introgression lines in rice (Oryza sativa L.)

Introgression Lines (ILs) carrying alien genomic segments in the homozygous state may or may not be able to contribute positively to the phenotype on account of replacement of cultivated genome segment, however, the genetic elite in heterozygous condition can be attributed to the presence of both recipient and donor genome complements. Therefore, overdominance or pseudo‐overdominance effect at the heterozygous loci is anticipated. Set of 318 ILs, carrying several genomic segments from “A” genome donor wild species, were used for developing test hybrids with CMS line PMS17A. Of these, three hybrids observed significant yield advantage (>25%) over recurrent parents and checks. Parental ILs of these hybrids viz., IL326, IL901 and IL951 carried 5.62%, 2.52% introgression from Oryza rufipogon and 6.71% from Oryza nivara, respectively. These ILs were also crossed with their recurrent parent to develop introgression line hybrids (ILHs) to observe the contribution of the alien segment(s), in the homozygous and heterozygous state. The traits studied have higher mean value when genomic segments from wild species were in the heterozygous state as compared to the homozygous state.     

Genetics of tolerance to high concentrations of boron in Brassica rapa

The inheritance of tolerance to high concentrations of boron in Brassica rapa was studied in F₂ and F₃ segregating populations. The F₁ hybrids were produced from genotypes contrasting in their reaction to boron. The F₁ hybrids responded similarly to the tolerant parent indicating that boron tolerance was dominant trait. Segregation patterns for boron tolerance in F₂ populations and F₃ derived families were established by the measurements of primary root length and tissue boron concentrations. The segregation ratios were explained in terms of two major genes interacting in a dominant epistatic manner to govern tolerance. Evaluation of selected tolerant and susceptible F₃ families indicated that tolerant families produced significantly longer primary roots as compared to susceptible families.     

Ecofriendly management of stem rot of berseem caused by Sclerotinia trifoliorum

Stem rot, incited by Sclerotinia trifoliorum Eriksson is one of the most devastating soil borne fungal pathogens of berseem (Trifolium alexandrinum L.) inflicting significant fodder and seed yield losses. Eleven plant extracts, six organic inputs, one elicitor and five organic and inorganic salts were assayed for their effectiveness against S. trifoliorum under in vitro conditions. Extracts of Aegle marmelos and Cymbopogan citrates showed complete mycelial inhibition of S. trifoliorum at 5% concentration. Among organic inputs, panchgavya and fermented cow urine recorded 100% inhibition to mycelial growth of stem rot pathogen at 10% concentration. Elicitor (chitosan) and salts namely copper sulphate and potassium carbonate provided complete mycelial inhibition of test pathogen under in vitro conditions at 0.1, 2.0 and 5.0% concentrations, respectively. The plant extracts, organic inputs and salts that exhibited highest mycelial inhibition to S. trifoliorum under in vitro conditions were evaluated for their antifungal efficacy under greenhouse and field experiments during rabi 2017–18 and 2018–19. The extracts of chitosan (78.58; 77.15%), panchgavya (75.99; 67.14%), copper sulphate 71.38; 61.18%) and A. marmelos (71.75; 56.24%) have recorded highest percent disease control as compared to untreated control in greenhouse and field trials in rabi 2017–18 and 2018–19, respectively. Significant increase in green fodder yield of berseem from 9.87 to 33.38% was also recorded after treatment with plant extracts, organic inputs and some salts. The current study showed that plant extracts, organic inputs and salts have potential for the management of stem rot of berseem.

     

Detection of quantitative trait loci for mungbean yellow mosaic India virus (MYMIV) resistance in mungbean (Vigna radiata (L.) Wilczek) in India and Pakistan

Yellow mosaic disease (YMD) is one of the major diseases affecting mungbean (Vigna radiata (L.) Wilczek). In this study, we report the mapping of the quantitative trait locus (QTL) for mungbean yellow mosaic India virus (MYMIV) resistance in mungbean. An F₈ recombinant inbred line (RIL) mapping population was generated in Thailand from a cross between NM10-12-1 (MYMIV resistance) and KPS2 (MYMIV susceptible). One hundred and twenty-two RILs and their parents were evaluated for MYMIV resistance in infested fields in India and Pakistan. A genetic linkage map was developed for the RIL population using simple sequence repeat (SSR) markers. Composite interval mapping identified five QTLs for MYMIV resistance: three QTLs for India (qYMIV1, qYMIV2 and qYMIV3) and two QTLs for Pakistan (qYMIV4 and qYMIV5). qYMIV1, qYMIV2, qYMIV3, qYMIV4 and qYMIV5 explained 9.33%, 10.61%, 12.55%, 21.93% and 6.24% of variation in disease responses, respectively. qYMIV1 and qYMIV4 appeared to be the same locus and were common to a major QTL for MYMIV resistance in India identified previously using a different resistant mungbean.