RESUMO
Winter oil rapeseed '18 R-1' (Brassica rapa L.) is a new variety that can survive in northern China where the extreme low temperature is -20 °C to -32 °C. It is different from traditional B. rapa and Brassica napus. In this study, the complete chloroplast (cp) genome of '18 R-1' was sequenced and analyzed to assess the genetic relationship. The size of cp genome is 153,494 bp, including one large single copy (LSC) region of 83,280 bp and one small single copy (SSC) region of 17,776 bp, separated by two inverted repeat (IR) regions of 26,219 bp. The GC content of the whole genome is 36.35%, while those of LSC, SSC, and IR are 34.12%, 29.20%, and 42.32%, respectively. The cp genome encodes 132 genes, including 87 protein-coding genes, eight rRNA genes, and 37 tRNA genes. In repeat structure analysis, 288 simple sequence repeats (SSRs) were identified. Cp genome of '18 R-1' was closely related to Brassica chinensis, B. rapa and Brassica pekinesis.
RESUMO
The purpose of this study was to realize the security of safe wintering of winter rapeseed in dry and cold regions of northern China. Experiments were conducted with 18 winter rapeseed (Brassica campestris) varieties at 57 sites from 2008 to 2013 to statistically analyze the wintering rate variation of different varieties in dry and cold regions of northern China. The results showed that, the wintering rate varied from 70% to 90% during the study period in different regions, which had no significant difference between different years and varieties, and had high stability and remarkable economic benefit. With Tianshui as a starting point of winter rapeseed planting, the wintering-safe regions included all Gansu Province , the south of Lasa and Linzhi of Xizang, the east of Minhe of Qinghai, up to Urumqi and Baicheng, and the south of Aletai, Tacheng, the east of Kashi of Xinjiang, it also included the regions along Yellow River eastward to Ningxia, the south of Linhe of Inner Mongolia, the north of Shaanxi, the vicinage of Qixian in Shanxi, Daming in Hebei, Tianjin, Beijing, the north of Weifang of Shandong, the south of Huludao of Liaoning and Yanbian of Jilin. Longyou 6, Longyou 7, Longyou 8 and Longyou 9 were the wintering-safe B. rapa varieties.
Assuntos
Agricultura , Brassica , Estações do Ano , ChinaRESUMO
Two transgenic potato lines with antisense AcInv gene and the non-transgenic varieties were used to test the reducing sugar and starch contents. The results indicated that the reducing sugar content increased and total starch content decreased in all samples after tubers were stored at 4 degrees C for 40 d. The reducing sugar content in tubers of transgenic line "Anti-AcInv Atlantic" and "Anti-AcInv Gannongshu No.2" were lower about 23% and 18% than those of Atlantic and Gannongshu No.2 (Table 1). The total starch and the amylopectin were also decreased by 1% and 1.3% in "Anti-AcInv Atlantic" and 1.4% and 1.7% in "Anti-AcInv Gannongshu No.2" respectively (Table 2). The proportions of amylose and amylopectin were lower in the transgenic lines than the non-transgenic varieties (Figs. 1 and 2). It was only 0.29 for "Anti-AcInv Atlantic" and 0.38 for "Anti-AcInv Gannongshu No.2". Meanwhile, there are fewer dark blue starch particles in transgenic tuber, which is less than in tuber of the non-transgenic varieties by paraffin-cut section method (Fig. 3). After the tubers were transferred to the storage temperature 15-17 degrees C for 20 d, the reducing sugar contents in tubers of the two transgenic lines were significantly lower than that of non-transgenic varieties. It was 0.23% for "Anti-AcInv Atlantic" and 0.24% for "Anti-AcInv Gannongshu No.2" (Table 1). It is suggested that the trans-antisense AcInv gene in the transgenic potato down-regulates the AcInv gene expression after the tubers were stored under low temperature.
