Grain size is one of the critical agronomic traits governing grain yield and quality in rice. However, the underlying genetic mechanisms that control grain size in rice are poorly understood. We used an introgression line derived from Zhonghui 8015 and Oryza rufipogon Griff. This introgression line was evaluated under two different environmental conditions to dissect the quantitative trait loci controlling grain size. Genome-wide association study (GWAS) was performed using 28 193 SNPs through a general linear model, and 56 significant SNPs on different loci associated with the 4 grain size traits were detected. Cloned genes including GS3 and qGL3 showed substantial effects on grain length and size. Seven new stable loci were identified with pleiotropic effects on grain size. Haplotype, gene expression analyses, combined gene-based associations, and functional annotations permitted the shortlisting of important dominant genes including GS3 and qGL3. 相似文献
This experiment was conducted to investigate effect of dried Sesbania sesban leaves supplementation on milk yield, feed intake and digestibility of Holstein Frisian X Zebu (Arado) crossbred dairy cows. Twelve cows at midlactation (155.83?±?4.49 days of lactation), second parity, and 442.21?±?3.40 kg average live body weight were randomly assigned to one of four dietary treatments according to a randomized complete block design. Cows were blocked according to their daily milk yield into three blocks of four animals each. Cows were fed a basal diet (control) or a basal diet supplemented with 1.25 kg/day dried Sesbania sesban leaves, 2 kg/day dried Sesbania sesban leaves and 2.75 kg/day dried Sesbania sesban leaves on a dry matter basis for 8 weeks. Total dry matter intake, nutrient intake, milk yield, dry matter digestibility, and nutrient digestibility showed significant variation among treatments. Cows supplemented with the highest level of Sesbania sesban (2.75 kg/day) had higher total dry matter and nutrient intake. Similarly, cows supplemented with 2 and 2.75 kg/day had higher milk yield than the nonsupplemented cows (up to 11.3 and 16.2%, respectively). Digestibility was lower for the nonsupplemented cows compared to cows supplemented with 2 and 2.75 kg/day dried Sesbania sesban leaves but statistically similar to the cows supplemented with 1.25 kg/day dried Sesbania sesban leaves. Supplementation with 2.75 kg/day Sesbania sesban resulted in higher organic matter digestibility (OMD) compared to the control. Crude protein digestibility (CPD), neutral detergent fiber digestibility (NDFD), and acid detergent fiber digestibility (ADFD) were significantly affected by Sesbania sesban supplementation. The nonsupplemented cows had lower CPD, NDFD, and ADFD. These results indicate that dried Sesbania sesban leaves supplementation to dairy increases total DM intake, digestibility, and milk yield.
A study was conducted in Tara Gedam and Abebaye forests l,northwestern Ethiopia to investigate the diversity,regeneration status,socio-economic importance and the factors causing destruction of the forests.A total of 30 plots,measuring 20 m ×20 m,were established along line transects laid across the forests.Participatory Rural Appraisal (PRA) method was employed to generate the socio-economic data.Primary data were collected by field observation,semi-structured interview with key informants and discussion with relevant stakeholders.A total of 143 woody species belonging to 114 genera and 57 families were recorded,and of all the species 44 (30.8%) were trees,57 (39.9%) trees/shrubs,33 (23.1%) shrubs and 9 (6.3%) lianas.The diversity and evenness of woody species in Tara Gedam forest are 2.98 and 0.65,respectively,and in Abebaye forest they are 1.31 and 0.31,respectively.The total density and basal area of woody species in Tara Gedam forest are 3001 individuals ha-1 and 115.36 m 2 ha-1,respectively,and in Abebaye forest the values are 2850 individuals ha-1 and 49.45 m 2 ha-1,respectively.The results on the importance value index (IVI) and DBH class distributions suggest that the species with low IVI value and poor regeneration status need to be prioritized for conservation.In the socio-economic survey,the responses from the key informants indicatedthat the forests are the major sources of fuelwood (90%),construction material (80%),timber (75%) and farm implements (55%).The forests are also sources of medicines,animal fodder,bee forage and edible fruits.Tara Gedam monastery,assisted by the local people who have strong religious belief and high respect to the monastery,has played a great role in the maintenance of the sacred forest since a long time.At present,the conservation efforts are made jointly by the monastery and institutions concerned with conservation.The major factors that cause destruction of the forests are livestock grazing,tree cutting for various purposes and farmland expansion.The implications of the results are discussed,and the recommendations are suggested for conservation,management and sustainable utilization of the forest ecosystems. 相似文献
The present study is a cost-benefit analysis of converting the current rotational forestry (RF) of Norway spruce stand into near-natural forestry (NNF) of beech, based on two representative soil conditions and visitors popular case areas in Denmark, considering welfare economic values of timber, recreation provision, and groundwater recharge. The study answers the major research question of how large the welfare economic values of recreation and groundwater benefits of the conversion are as compared with timber benefits. The net present values (NPV) of the benefits were calculated for an infinite time horizon at a 3 % discount rate. The results reveal that converting into NNF would result in a NPV of at least 6,832 € ha?1 from use values of recreation and water benefit on a site with good soil and a high visitor frequency, as is typical in the eastern part of Denmark. On a site in the west of the country, with poor growth conditions and a lower visitor frequency, the gain is still substantial, namely 5,581 € ha?1. These benefits though come at a cost of 3,375 and 6,206 € ha?1 from timber production, respectively. This means that the economic value of use values of recreation and water benefits outweighs the loss of timber on good soil conditions but not on poor soil conditions. 相似文献
正To investigate the genetic bases of grain weight (GW), a set of 76 chromosome segment substitution lines (CSSLs, BC4F5) were developed from the cross between Xieqingzao B (XQZB) and Zhonghui 9308 (ZH9308) using a marker-assisted selection (MAS).All substituted segments represented by 120 markers in those lines covered 96.7% of the donor parent (ZH9308). Consequently, 相似文献
Tropical Animal Health and Production - Accurate performance evaluation and genetic parameters estimation are the prerequisites for any successful genetic improvement program. This study was... 相似文献