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141.
To examine the effect of zinc (Zn) application method on the utilization of phosphorus (P) from applied P fertilizer, a field experiment was conducted on basmati rice–wheat rotation with combinations of Zn levels (0, soil application of 2.5 kg Zn ha 1 and two foliar applications of 2.0 kg Zn ha 1) and P levels (0, soil application of 8.7, 17.5 and 26.2 kg P ha 1). The highest pooled grain yields of basmati rice and wheat were obtained with soil application of 17.5 kg P ha 1 and foliar applications of 2 kg Zn ha 1. Foliar applications of Zn increased the P concentration in grain and straw and the total P uptake by basmati rice and the P concentration in flag leaves of wheat significantly, while soil or foliar application of Zn increased the total P uptake of wheat. Phosphorus application increased the Zn concentration in flag leaves, grain and straw of basmati rice and in grain and straw of wheat and the total Zn uptake of both crops. Phosphorus levels up to 17.5 kg P ha 1 increased utilization efficiency of soil or foliar application of Zn. Zinc application increased the P utilization efficiency of basmati rice and wheat up to 17.5 kg P ha 1 level; foliar Zn application was more effective in a wheat crop than a rice crop.  相似文献   
142.
A field study conducted for two crop cycles of five cropping systems supplied with six nutrient combinations at the Indian Agricultural Research Institute, New Delhi indicated that the cropping systems having a legume increased organic C content over initial level by 0.02?–?0.05%, available N by 3.5?–?14.1?kg ha???1, whereas the rice-wheat cropping system resulted in a reduction in organic C and available N over initial level by 0.05% and 1.5?kg ha???1, respectively after 2 years of study. Rice-potato-mungbean cropping system resulted in a negative balance of available P and rice-clover cropping system had a negative balance of both available P and available K content in soil and thus call for adequate P and K fertilization. Application of P and K helped in building up their content in soil; NPK?+?FYM showed the highest increase in organic C, available N, available P and available K content in soil. These results suggest the inclusion of a legume in a cropping system for maintaining organic C and available N in soil and adequate P and K fertilization for arresting the depletion of available P and K content in soil. Integrated nutrient management is one of the best methods for resilience of soil fertility under rice-wheat cropping system.  相似文献   
143.
The objective of the study carried out in the Upper Oueme Catchment in Benin (West Africa) was to assess the nutrient status in yam (Dioscorea rotundata) through the Diagnostic and Recommendation Integrated System (DRIS), to compare yield, foliar nutrient concentrations and the variance of nutrients of low-and high-yielding groups. Field experiments were carried out in 2001 and 2002 using a randomized complete block design with four treatments, 2001: n = 80, 2002: n = 109) at three sites: Beterou, Dogue, and Wewe. Nitrogen (N), followed by potassium (K), phosphorus (P), and magnesium (Mg) were identified as the most limiting nutrients in 2001 whereas sulfur (S) followed by N was identified as most limiting ones in 2002. Imbalanced nutrition was observed in both the years but was higher in 2001 compared in 2002. They may be utilized as a basis for calibrating the fertilization program of yam.  相似文献   
144.
145.
In view of the difficulties in stand volume estimation in natural forests, we derived real form factors and models for volume estimation in these types of forest ecosystems, using Katarniaghat Wildlife Sanctuary as a case study. Tree growth data were obtained for all trees (dbh >10 cm) in 4 plots (25 × 25 m) randomly located in each of three strata selected in the forest. The form factor calculated for the stand was 0.42 and a range of 0.42 0.57 was estimated for selected species (density >10). The parameters of model variables were consistent with general growth trends of trees and each was statistically significant. There was no significant difference (p>0.05) between the observed and predicted volumes for all models and there was very high correlation between observed and predicted volumes. The output of the performance statistics and the logical signs of the regression coefficients of the models demonstrated that they are useful for volume estimation with minimal error. Plotting the biases with respect to considerable regressor variables showed no meaningful and evident trend of bias values along with the independent variables. This showed that the models did not violate regression assumptions and there were no heteroscedacity or multiculnarity problems. We recommend use of the form factors and models in this ecosystem and in similar ones for stand and tree volume estimation.  相似文献   
146.
Leaves of multipurpose tree species (those providing more than one function or product of human use) can serve as sources of fer-tilizer for nutrient supply, especially nitrogen (N). In this study chop...  相似文献   
147.
Genetic improvement of sugar content in sugarcane would benefit from the availability of sufficient DNA markers and a genetic map. Genetic linkage maps were constructed to identify quantitative trait loci (QTLs) for seedling brix (SB), brix (B), sucrose percent in juice (SUC), stalk number (SN), stalk length (SL), stalk diameter (SD), internodes (INT), number of green leaves (NGL), at three crop cycles across seven environments in a segregating population with 207 individuals derived from a bi-parental cross of sugarcane elite cultivars. Linkage analysis led to the construction of eight linkage groups (LGs) for Co86011 and sixteen LGs for CoH70. The combined length of the two linkage maps was 2606.77 cM distributed over 24 LGs. 31 QTLs were identified: 2 for SB, 7 for B, 6 for SUC, 4 for SN, 1 for SL, 3 for SD, 6 for INT and 2 for NGL at LOD scores ranging from 2.69 to 4.75. 7 QTLs (22 %) had stable effect across crop year and locations. Markers from parents were found to be associated with both positive and negative effect on all of the traits analyzed. The most important QTLs intervals identified in this study using single-dose marker, were qB2, qSUC2, qINT2 and qB2, qSUC2, qSL2, qINT2 located between SSR markers UGSM31548 and UGSM31649. These QTLs could be put into use in marker assisted breeding.  相似文献   
148.
Abstract

Larval rohu Labeo rohita were fed four different diets: three of the diets contained Achyranthes aspera (prickly chaff-flower) seeds at 0.10% (D1), 0.25% (D2), or 0.50% (D3); the fourth diet was a control diet (D4; no A. aspera supplementation). After 70 d, the rohu were injected intraperitoneally with live Aeromonas hydrophila. Mortality of fish was recorded for 7 d. In the D4 group, the first mortality was observed within 12 h of exposure, whereas in the D1–D3 treatment groups, mortality was first observed at 24 h postexposure. In the D4 group, 50% of fish died within 72 h of exposure, whereas in the D3 group, 10–15% mortality occurred between 72 and 84 h. The cumulative mortality rate was 50% for D4, 40% for D1, 35% for D2, and 15% for D3. Total tissue protein level in the larvae was higher for the D2 and D3 groups than for the other groups. Glutamic oxaloacetic transaminase, glutamate pyruvate transaminase, and thiobarbituric acid reactive substance levels were significantly lower in D3 larvae than in the other groups, whereas lysozyme and nitric oxide synthase levels were significantly higher in D3 larvae compared with the other groups. Dietary supplementation with A. aspera seeds at the 0.50% level provided protection against oxidative stress, prevented tissue damage, and enhanced disease resistance in rohu larvae.

Received December 26, 2011; accepted May 7, 2012  相似文献   
149.
This study was carried out to compare the post‐thaw cryosurvival rate and the level of apoptosis in vitro produced zona‐free cloned buffalo blastocysts subjected to slow freezing or vitrification in open‐pulled straws (OPS). Zona‐free cloned embryos produced by handmade cloning were divided into two groups and were cryopreserved either by slow freezing or by vitrification in OPS. Cryosurvival of blastocysts was determined by their re‐expansion rate following post‐thaw culture for 22–24 h. The post‐thaw re‐expansion rate was significantly (p < 0.05) higher following vitrification in OPS (71.2 ± 2.3%) compared with that after slow freezing (41.6 ± 4.8%). For examining embryo quality, the level of apoptosis in day 8 frozen‐thawed blastocysts was determined by TUNEL staining. The total cell number was not significantly different among the control non‐cryopreserved cloned embryos (422.6 ± 67.8) and those cryopreserved by slow freezing (376.4 ± 29.3) or vitrification in OPS (422.8 ± 36.2). However, the apoptotic index, which was similar for embryos subjected to slow freezing (14.8 ± 2.0) or OPS vitrification (13.3 ± 1.8), was significantly (p < 0.05) higher than that for the control non‐cryopreserved cloned embryos (3.4 ± 0.6). In conclusion, the results of this study demonstrate that vitrification in OPS is better than slow freezing for the cryopreservation of zona‐free cloned buffalo blastocysts because it offers a much higher cryosurvival rate.  相似文献   
150.
For investigating the effects of physiologically relevant heat shock, buffalo oocytes/embryos were cultured at 38.5°C (control) or were exposed to 39.5°C (Group II) or 40.5°C (Group III) for 2 h once every day throughout in vitro maturation (IVM), fertilization (IVF) and culture (IVC). Percentage of oocytes that developed to 8‐cell, 16‐cell or blastocyst stage was lower (p < 0.05) and the number of apoptotic nuclei was higher (p < 0.05) for Group III > Group II > controls. At both 8–16‐cell and blastocyst stages, relative mRNA abundance of stress‐related genes HSP 70.1 and HSP 70.2 and pro‐apoptotic genes CASPASE‐3, BID and BAX was higher (p < 0.05) in Groups III and II than that in controls with the exception of stress‐related gene HSF1. Expression level of anti‐apoptotic genes BCL‐XL and MCL‐1 was also higher (p < 0.05) in Groups III and II than that in controls at both 8–16‐cell and blastocyst stages. Among the genes related to embryonic development, at 8–16‐cell stage, the expression level of GDF9 was higher (p < 0.05) in Group III than that in controls, whereas that of GLUT1, ZAR1 and BMP15 was not significantly different among the three groups. At the blastocyst stage, relative mRNA abundance of GLUT1 and GDF9 was higher (p < 0.05) in Group II than that in controls, whereas that of ZAR‐1 and BMP15 was not affected. The results of this study demonstrate that exposure of buffalo oocytes and embryos to elevated temperatures for duration of time that is physiologically relevant severely compromises their developmental competence, increases apoptosis and affects stress‐, apoptosis‐ and development‐related genes.  相似文献   
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