SOME ABNORMAL FLOWERS OF ARGEMONE MEXICANA AND THEIR BEARING ON THE MORPHOLOGY OF THE GYNOECIUM OF PAPAVERACEAE

Abnormal flowers of Argemone mexicana are described in whichthe gynoecium has been transformed into a cup with lobed marginor into free leafy carpels. The number of lobes or leafy carpelsin such gynoecia is found to vary from three to five. This agreeswith the general view of systematists regarding the number ofcarpels composing the gynoecium in this species, and is againstthe views of Saunders and Dickson who postulate twice as manycarpels.     

Transverse Relaxation Time of Leaf Water Protons and Membrane Injury in Wheat (Triticum aestivum L.) in Response to High Temperature

The relationship between high temperature stress injury andtemperature dependence of the transverse relaxation time (T₂)of leaf water was examined using NMR in four cultivars of wheatdiffering in their sensitivity to high temperature stress. TheT₂declined with increasing temperature between 25 and 35 °C.A comparison of relative injury based on electrolyte leakageand T₂, between 40 and 50 °C, indicated that while membranepermeability increased with increasing temperature there wasan increase in T₂until 44 and 48 °C in susceptible and tolerantcultivars respectively, followed by a sharp decline. This patternof change in T₂with increasing temperature was consistent whetherthe same or different samples were used for each treatment temperature.Loss of temperature dependence of T₂after heat killing indicatedirreversible changes in T₂, probably due to the loss of membraneintegrity. Heat tolerant varieties, which suffered less membraneinjury, had a higher T₂compared to susceptible varieties. Tolerantvarieties also maintained the T₂of leaf water protons to highertemperatures than did sensitive varieties. This NMR-based, non-invasive,rapid technique could be used to efficiently detect heat injuryin leaf tissues. Copyright 1999 Annals of Botany Company Membrane integrity, transverse relaxation time, high temperature stress, Triticum aestivum L.     

Production protocol for and storage efficacy of an anthocorid predator Cardiastethus exiguus Poppius

Cardiastethus exiguus Poppius is an indigenous anthocorid predator of eggs and neonates of the notorious pest,coconut black-headed caterpillar Opisina arenosella Walker in India.At the National Bureau of Agriculturally Important Insects(Indian Council of Agricultural Research),Bangalore,India,a simple mass production protocol was developed for multiplying C.exiguus using UV-irradiated eggs of alternate laboratory host Corcyra cephalonica Stainton.Field evaluation of the predator in the states of Kerala and Karnataka indicated that this predator could bring about a significant reduction in the pest population.Subsequently,the need was felt to investigate the storage efficacy of the eggs and adults of C.exiguus so that sufficient numbers could be accumulated and transportation of the predator could be planned for field releases.Low temperature storage studies indicated that C.exiguus eggs can be safely stored for up to 5 days at 10℃ and 10 days at 15℃ and incubation period could be staggered for up to 10 and 13 days,respectively.The longevity of the C.exiguus adults was significantly reduced due to low temperature storage.However,for adult females,a storage temperature of 15℃ for 15 days could be recommended as they could live for a more than a month after removal from storage and their progeny production was comparable to that of the control adults.     

Complete mitochondrial genome of threatened mahseer <Emphasis Type="Italic">Tor tor</Emphasis> (Hamilton 1822) and its phylogenetic relationship within Cyprinidae family

The mahseers (Tor, Neolissochilus and Naziritor) are an important group of fishes endemic to Asia with the conservation status of most species evaluated as threatened. Conservation plans to revive these declining wild populations are hindered by unstable taxonomy. Molecular phylogeny studies with mitochondrial genome have been successfully used to reconstruct the phylogenetic tree and to resolve taxonomic ambiguity. In the present study, complete mitochondrial genome of Tor tor has been sequenced using ion torrent next-generation sequencing platform with coverage of more than 1000 ×. Comparative mitogenome analysis shows higher divergence value at ND1 gene than COI gene. Further, occurrence of a distinct genetic lineage of T. tor is revealed. The phylogenetic relationship among mahseer group has been defined as Neolissochilus hexagonolepis ((T. sinensis (T. putitora, T. tor), (T. khudree, T. tambroides)).     

AGE-RELATED ALTERATIONS IN HUMAN CHROMOSOME COMPOSITION AND DNA CONTENT IN VITRO DURING SENESCENCE

Different theories of ageing involving somatic mutations, error catastrophe, compensation and repair, and programmed ageing were subjected to analysis for their feasibility from experimental data. Due to the relative difficulty of carrying out longitudinal studies in human subjects in vivo and the long periods involved, most of these experiments dealt with in vitro systems. I. Fibroblast cells in culture were found to be ideal materials for demonstrating senescence for a particular species and at the terminal end the cultures showed certain changes associated with age. II. It appears that the ideas regarding the alterations in DNA content at the terminal stages of the culture or otherwise are related to the tissues concerned and the duration of the cultured condition. III. The importance of DNA content specially related to the concept of stability of the DNA strand supports indirectly the error catastrophe theories. The rate of net DNA synthesis, the size of the replicon and duration of S phase is reported not to change during in vitro ageing. The regulation system of DNA replication may however change, but this alteration does not affect the DNA replication machinery. Following cell fusion studies it has been hypothesized that senescent human diploid fibroblasts contain a diffusible inhibitor which blocks cells at G₁ phase. Some immortal cell lines like HeLa and SV40-transformed cells would contain a dominant inducer that could override or inactivate the putative inhibitor, the nature of which is not yet clear. IV. DNA repair competence of fibroblast cultures is reported to decline near the end of in vitro life-span. However, it has been noted that the human skin fibroblasts from both young and old donors are equally proficient in repairing damage by UV light. V. The replication patterns of chromosomes from both senescent embryonic fibroblasts and early-passage adult skin fibroblasts were essentially identical. There were very few differences between the early-passage embryonic and adult skin cells. It was concluded that the terminal replication pattern of fibroblasts changes very little with cellular ageing. VI. A statistically significant increase in sister chromatid exchange frequency has been reported during the terminal part of fibroblast cultures. VII. Electron-microscopic studies have confirmed the increased organization of microfillaments into bundles in senescent cells. The presence of a rigid cytoskeletal structure may contribute in part to the inability of such cells to replicate. VIII. Age-related increase in nuclear proteins was attributed to accumulation of residual acid proteins. Densitometric analysis showed that histone HI was low in late-passage cells and H₄ fraction increased relatively at the terminal phase. IX. In contrast to age-matched controls, fibroblasts cultured from progeria and Werner's syndrome undergo significantly low population doubling. Metaphase plates from these patients demonstrated a much higher frequency of chromosomal abnor malities than normal fibroblasts. Frequency of sister chromatid exchange in cells from Fanconi's anaemia did not show any significant change as compared with control sets. X. Significantly lower Feulgen DNA values have been recorded from lymphocytes of the elderly as compared with younger ones, indicated by hypodiploidy as well as by the individual amounts of euchromatin and heterochromatin. However, later data from flow-cytometric measurements indicated that DNA content was the same for all age groups. XI. The UV-induced unscheduled DNA synthesis in lymphocytes of 80 to 90 year-old individuals was reduced as compared to younger persons. However, the rate of repair of DNA strand breaks is apparently constant in all the age groups. XII. Increase in aneuploidy from lymphocyte cultures of aged individuals has been recorded by many workers. XIII. Significantly lower titres of serine, threonine, histidine, ornithine and lysine have been observed in aged persons, and only the first three decreased equally in both sexes. Some of the amino acids were influenced by sex hormones. XIV. Study of the frequency of spontaneous sister chromatid exchanges showed that neither intra-individual variation between replicate cultures established from the same blood sample nor variation among samples from the same individual initiated at different times was significant. However, sensitivity to induced sister chromatid exchange is reported to increase with age.     

Extractable protein from the by-product vegetation of some cole and root crops

The amount of extractable protein from leaves taken at the time of harvest of the edible part was determined for brassicas, beet root, turnip and radish. These leaves yielded much more dry matter and total nitrogen per ha than did the edible material. With only one pulping, from 35 to 59% of protein nitrogen could be extracted and the yields of extractable protein from the leaves ranged from 76 to 170 kg/ha. It would be advantageous to obtain protein from these leaves which otherwise are discarded.