Sequence variation in the bolting time regulator BTC1 changes the life cycle regime in sugar beet

In beet production, flowering is an undesirable trait which drastically reduces yield. BOLTING TIME CONTROL 1 (BTC1) and BvBBX19 are major floral regulators in beet. Their proteins have been suggested to interact to jointly regulate their downstream targets BvFT1 and BvFT2. Annual and biennial BTC1 haplotypes differ by six non‐synonymous SNPs and a large insertion in the promoter of the biennial btc1 allele. We describe a new BTC1 allele which displays three nucleotide polymorphisms in the coding sequence and an 8‐bp insertion in the promoter region compared to the annual BTC1_d allele. The protein lacks a low‐complexity region, which likely alters its suggested ability to bind BvBBX19. Our findings demonstrate that little sequence variation in BTC1 is sufficient to turn an annual into a biennial genotype. Our results shed new light on the evolution of cultivated beets, and the identified btc1_l allele offers new possibilities to breed winter beets.     

复合益生素对生长育肥猪生产性能、盲肠菌群及代谢产物的影响

试验旨在研究饲粮中添加复合益生素(JS菌)对生长育肥猪生产性能、盲肠菌群、挥发性脂肪酸及蛋白质腐败产物的影响。试验选择120头体重10 kg左右的健康DLY仔猪,随机分为对照组、抗生素组、0.1%JS菌组和0.2%JS菌组,每组5个重复。结果表明:与对照组相比,添加0.2%JS菌显著提高试猪30~50 kg阶段的平均日增重和采食量(P0.05);添加0.1%JS菌显著提高试猪80~100 kg阶段的平均日增重(P0.05);从试验全期来看,抗生素组、0.1%JS菌组和0.2%JS菌组试猪平均日增重和采食量均有所提高,但各组间差异不显著(P0.05)。添加JS菌趋于增加盲肠内容物乳酸杆菌数量,减少大肠杆菌数量(P0.05),从而提高二者的比值,分析PCR-DGGE图谱发现添加JS菌对菌群多样性和相似性也有一定影响。与对照组相比,0.1%JS菌组和0.2%JS菌组盲肠内容物乙酸含量分别提高2.35倍和2.99倍,丁酸含量分别提高58.87%和62.10%,挥发性盐基氮含量分别降低31.91%和28.53%(P0.05)。在本试验条件下,添加JS菌对生长育肥猪的生产性能有一定改善,效果与抗生素基本相当,这可能与其对肠道健康的保护作用有关。