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11.
PV Hobbs JS Reid RA Kotchenruther RJ Ferek R Weiss 《Science (New York, N.Y.)》1997,275(5307):1776-1778
Airborne measurements in smoke from biomass burning in Brazil have yielded optical parameters that permit an improved assessment of the effects of smoke on Earth's radiation balance. The global-mean direct radiative forcing due to smoke from biomass burning worldwide is estimated to be no more than about -0.3 watt per square meter (cooling), compared with +2.45 watts per square meter (warming) due to anthropogenic greenhouse gases. On regional scales, direct radiative forcing due to smoke can be large and might indirectly affect global climate. 相似文献
12.
Alterations in inheritance pattern and level of cytosine DNA methylation,and their relationship with heterosis in rice 总被引:2,自引:0,他引:2
K. Sakthivel K. Girishkumar G. Ramkumar V. V. Shenoy S. T. Kajjidoni P. M. Salimath 《Euphytica》2010,175(3):303-314
Novel hybrid-specific/heterotic gene expression patterns observed from expression studies suggest the need to characterize
the underlying regulatory mechanism(s) to reveal the biological basis of heterosis in crop plants. To gain an insight into
the molecular basis of heterosis in rice, we investigated the inheritance pattern and level of cytosine methylation, a major
epigenetic regulatory mechanism, in the leaf tissue of an elite Indian rice hybrid KRH2 and its parents at three stages (15 day-old,
35 day-old seedling and flag leaf) and their correlation with heterosis using methylation-sensitive amplification polymorphism
(MSAP) technique. In contrast to parents, the level of methylation was high during initial growth stages and reduced as the
hybrid grew. Even though, a majority of cytosine methylation profiles were transmitted to hybrid at all stages, a considerable
level (25.4%) of cytosine methylation pattern was observed to be novel in hybrid and some of these altered loci were identified
to code for known/hypothetical proteins. It was also observed that demethylation events occurred more predominantly during
early stages than hypermethylation while the frequency of demethylation events decreased in flag leaf with a remarkable increase
in hypermethylation in the hybrid. These bi-directional events in methylation in KRH2 were validated in six hybrids with different
levels of grain yield heterosis and the level of cytosine methylation in the hybrid was observed to be significantly correlated
with heterosis. 相似文献
13.
Early-maturity helps chickpea to avoid terminal heat and drought and increases its adaptation especially in the sub-tropics.
Breeding for early-maturing, high-yielding and broad-based cultivars requires diverse sources of early-maturity. Twenty-eight
early-maturing chickpea germplasm lines representing wide geographical diversity were identified using core collection approach
and evaluated with four control cultivars in five environments for 7 qualitative and 16 quantitative traits at ICRISAT Center,
Patancheru, India. Significant genotypic variance was observed for days to flowering and maturity in all the environments
indicating scope for selection. Genotypes × environment interactions were significant for days to flowering and maturity and
eight other agronomic traits. ICC 16641, ICC 16644, ICC 11040, ICC 11180, and ICC 12424 were very early-maturing, similar
to or earlier than control cultivars Harigantars and ICCV 2. The early-maturing accessions produced on average 22.8% more
seed yield than the mean of four control cultivars in the test environments. ICC 14648, ICC 16641 and ICC 16644 had higher
100-seed weight than control cultivars, Annigeri and ICCV 2. Cluster analysis delineated three clusters, which differed significantly
for all the traits. First cluster comprised three controls, ICCV 96029, Harigantars, ICCV 2 and two germplasm lines, ICC 16644
and ICC 16641, second cluster comprised 13 germplasm lines and control cultivar Annigeri, and third cluster comprised 13 germplasm
lines. Maturity was main basis of delineation of the first cluster from others. Plot yield and its associated traits were
the main basis for delineation of the second cluster from the others. Identification of these diverse early-maturing lines
would be useful in breeding broad-based, early-maturing and high-yielding cultivars. 相似文献
14.
ZS Perényi O Szenci J Sulon PV Drion & JF Beckers 《Reproduction in domestic animals》2002,37(2):100-104
Pregnancy‐associated glycoproteins (PAGs) constitute a large family of glycoproteins that are synthesized in the superficial layer of the ruminant placenta according to a spatial and temporal expression pattern. When PAGs are released in the maternal blood they can be used for pregnancy diagnosis, pregnancy follow‐up and for the monitoring of the trophoblastic function. Three different radioimmunoassay systems (RIA 1, RIA 2 and RIA 3) using antisera produced against PAG I67 (RIA 1), PAG55+62 (RIA 2) and PAG55+59 (RIA 3) were used in this investigation in order to measure the PAG concentration in plasma samples withdrawn from pregnant cows and heifers during different periods following artificial insemination (AI). These systems were able to detect PAG molecules in the maternal blood as early as 21 days after AI in different concentrations (RIA 1: 0.43 ± 0.24 ng/ml, mean ± SD; RIA 2: 0.48 ± 0.24 ng/ml; RIA 3: 0.64 ± 0.37 ng/ml). On days 32 and 42 RIA 2 (4.30 ± 1.32 ng/ml and 5.56 ± 1.95 ng/ml) and RIA 3 (4.17 ± 1.15 ng/ml and 5.60 ± 1.89 ng/ml) presented significantly (p < 0.0001) higher PAG concentrations than those of RIA 1 (2.43 ± 0.81 ng/ml and 4.01 ± 1.48 ng/ml), respectively. After day 21, significant correlations (p < 0.0001; r ≥ 0.929) were determined between the three systems. Additionally the three individual PAG profiles presented in this study showed that PAG molecules secreted in the maternal blood between 21 and 50 days after AI were better recognized by the RIA 2 and RIA 3 systems. This study clearly indicated that the ability of a RIA test to recognize PAG molecules in the maternal blood can be improved by carefully selecting the antiserum. 相似文献
15.
Modulatory Effect of Fenugreek Seed Mucilage and Spent Turmeric on Intestinal and Renal Disaccharidases in Streptozotocin Induced Diabetic Rats 总被引:1,自引:0,他引:1
Kumar GS Shetty AK Salimath PV 《Plant foods for human nutrition (Dordrecht, Netherlands)》2005,60(2):87-91
To elucidate the effect of feeding fenugreek seed mucilage and spent turmeric (10%) on disaccharidases activities, the specific activities of intestinal and renal disaccharidases viz., sucrase, maltase and lactase were measured in streptozotocin induced diabetic rats. Specific activities of intestinal disaccharidases were increased significantly during diabetes and amelioration of these activities during diabetes was clearly visible by supplementing fenugreek seed mucilage and spent turmeric in the diet. However during diabetes renal disaccharidases activities were significantly lower than those in the control rats. Fenugreek seed mucilage and spent turmeric supplementations were beneficial in alleviating the reduction in maltase activity during diabetes, however not much change in the activities of sucrase and lactase was observed upon feeding. This positive influence of feeding fenugreek seed mucilage and spent turmeric on intestinal and renal disaccharidases clearly indicates their beneficial role in the management of diabetes. 相似文献