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As a multifunctional cytokine, transforming growth factor‐beta1 (TGF‐β1) was detected in the utero‐placental interface during early pregnancy in the pig and believed to enhance trophoblast attachment to the endometrium. In this experiment, we selected TGF‐β1 as the candidate gene affecting litter size in pigs. Four polymorphic loci of TGF‐β1 gene were found by PCR‐SSCP (single‐strand conformation polymorphism) in Large white sows (n = 567): C→T mutation at 33nt in the intron 4; G→A mutation at 179nt in the intron 6; C→T mutation at 1043nt in the intron 6; GG→AA linkage mutations at 2490nt and 2494nt respectively. We haplotyped these SNPs as: CGCAA (denote as P) and TATGG (denote as K). The effects of three haplotypic combinations (HCs) of PP, PK and KK on litter sizes were investigated by a linear model. It was found that for the first parity litters, the least squares mean for total number born (TNB) of KK was 1.02 piglets/litter, higher than that of PK (p < 0.05), 0.49 piglets/litter higher than that of PP (p > 0.1). There were no significant differences between HCs on the second parity. The result indicated that KK HCs was significantly associated with pig litter size. 相似文献
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Mark H Crawford K. Bell S. Kodur YP Dang 《Journal of Crop Science and Biotechnology》2018,21(1):13-22
Strategic tillage (ST), an occasional tillage in a continuous no-till (NT) farming system, is already being utilized by many landholders in the Northern Grains Region (NGR) of Australia to control weeds. But the impact on productivity (yield), both short- and long-term, has been largely under investigated. This study focused on yield data from 14 on-farm ST in NT experiments from 2012 to 2014 (3 years/4 seasons) and the comparison of the re-interpreted results of a long-term (27 years) tillage experiment. This study explored production impacts of tillage on long-term NT systems over the short and longer term. Results from tillage-frequency studies across the NGR demonstrated that overall grain yield was not significantly impacted. A long-term tillage trial at Biloela showed wheat (Triticum aestivum) and sorghum (Sorghum bicolor) grain yields were similar across no till, stubble mulch and reduced tillage treatments, these in turn were all significantly higher than aggressive tillage without stubble retention treatments. Dealing with increased herbicide resistance often associated with reduced tillage and no-till systems poses a real time issue with landholders in the NGR. This analysis of historical yield data together with the more recent strategic tillage data can aid in selecting the appropriate soil management option by providing tillage impacts on yield. 相似文献
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