Wyniki wyszukiwania - Biblioteka Nauki

1

Year round plasma leptin and androgen concentrations in a tropical bat

100%

Singh U. P. , Krishna A. , Bhatnagar K. P.

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nr 2

EN

The detailed reproductive patterns and their associated endocrine characteristics have been documented only for a few species of bats. The objective of this study was to examine seasonal changes in plasma concentrations of leptin and compare it with the changes in body mass, circulating concentrations of testosterone, androstenedione and its correlation with prolonged survival of sperm during winter dormancy in the male sheath-tailed batTaphozous longimanus Hardwicke, 1825. Six bats were captured every month for three consecutive years during 2002 to 2005 from Varanasi, a subtropical part of India. The changes in the body mass were positively correlated with circulating concentration of leptin. Leptin concentration reached a peak (14 ng/ml) in November coinciding with peak body mass. Leptin levels declined during other months of the year except for a rise in March and August. Plasma leptin was positively correlated with androstenedione concentration, but did not show significant correlation with testosterone level. We noticed a significant increase in testosterone secretionin vitro in response to leutinizing hormone (LH) stimulation. However, we did not notice any increase in testosterone or androstenedione secretionin vitro in response to leptin stimulation. Plasma leptin concentration did not show any correlation with testis mass in this study. The higher concentration of testosterone and androstenedione may be responsible for the prolonged survival of sperm in the epididymidies and higher levels of leptin in November may be responsible for maintaining reproductive function during winter dormancy. We suggest that inT. longimanus, higher leptin concentrations in November may be responsible for the gonadal recrudescence and reproductive response during winter dormancy is modified by energy availability and by changing leptin concentrations during this period.

2

Role of air and light in sclerotial development and basidiospore formation in Sclerotium rolfsii

88%

Maurya S. , Singh U. P. , Singh R. , Singh A. , Singh H. B.

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tom 50

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nr 2

206-209

EN

Sclerotium rolfsii is one of the devastating soil-borne phytopathogens which causes severe loss at the time of seedling development. It also causes leaf spots in several crops and wild plants. Petri plates, containing potato dextrose agar medium, were inoculated with S. rolfsii. Two-third area of three, 50% area of three and 100% area of other three plates were sealed with cellophane tape. The other three plates were not sealed. All the plates were incubated at 27±2°C. Two sets of such plates were prepared. One set was incubated in light whereas the other set in the dark. There was no significant difference in mycelial growth and number of sclerotia among them but significant difference was observed when compared to the control, i.e. the plates which were not sealed. Sclerotium and basidiospore formation were directly influenced by air as completely sealed plates failed to produce sclerotia and basidiospores. Basidiospores were produced abundantly in the light and in the dark conditions in unsealed plates only on Cyperus rotundus rhizome meal agar medium.

PL

Sclerotium rolfsii jest patogenem glebowym, powodującym uszkodzenia siewek, sprawcą plamistości liści w kilku uprawach i na dzikich roślinach. W badaniach wykorzystano płytki Petriego zawierające pożywkę agarową z glukozą, zaszczepioną grzybem S. rolfsii. Dwie trzecie powierzchni trzech płytek, 50% powierzchni następnych trzech oraz 100% powierzchni kolejnych trzech zaklejono taśmą celofanową. Trzy płytki nie były zalepione. Wszystkie były inkubowane w 27±2°C. Przygotowano dwa komplety takich płytek. Jeden był inkubowany na świetle, drugi w ciemności. Nie było istotnych różnic między nimi we wzroście grzybni i liczbie sklerocjów, ale istotne różnice zaobserwowano w porównaniu z kontrolą, tj. niezaklejonymi płytkami. Na wytwarzanie sklerocjów i bazidiospor bezpośrednio wpływało powietrze, ponieważ nie stwierdzono istotnych różnic we wzroście grzybni i liczbie sklerocjów w porównaniu z kontrolą, tj. z płytkami, które nie były zaklejone. Tylko na pożywce agarowej z mączką z rozłogów Cyperus rotundus, bazydiospory powstawały licznie na świetle i w ciemności w niezaklejonych płytkach.

3

Fungal spore germination inhibition by alkaloids dehydrocorydalmine and oxyberberine

76%

Singh A. , Singh S. , Singh S. , Singh T. D. , Singh V. P. , Pandey V. B. , Singh U. P.

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nr 3

287-289

EN

The alkaloids dehydrocorydalmine and oxyberberine isolated from Argemone mexicana were assessed against spore germination of some fungi, e.g., Alternaria cajani, Bipolaris sp., Helminthosporium sp., Fusarium udum and Curvularia sp. While dehydrocorydalmine inhibited 100% spore germination of the fungi Helminthosporium sp. and Curvularia sp. at 5 000 ppm, oxyberberine showed similar activity against spore germination of Bipolaris sp. and Curvularia sp. All the five fungi were significantly inhibited at 1 000 to 5 000 ppm concentrations.

PL

Określano wpływ alkaloidów dehydrokorydalminy i oksyberberyny wyosobnionych z Argemone mexicana na kiełkowanie zarodników niektórych grzybów, w tym Alternaria cajani, Bipolaris sp., Helminthosporium sp., Fusarium udum i Curvularia sp. Podczas gdy dehydrokory-dalmina inhibowała w 100% kiełkowanie zarodników grzybów Helminthosporium sp. i Curvularia sp. w stężeniu 5 000 ppm, oksyberberyna wykazywała podobną aktywność przeciwko kiełkowaniu zarodników Biopolaris sp. i Curvularia sp. Wszystkie pięć grzybów było istotnie inhibitowane w stężeniach od 1 000 do 5 000 ppm.