四川溪洛渡水库库区雷波至金阳段翼手类调查

1999年5～7月,对溪洛渡水库库区（雷波至金阳一线河谷地带〈包括永善〉,海拔2000 m以下）翼手类进行了调查.共计调查了20个洞穴和沿线房屋.调查结合历史资料确认溪洛渡水库库区有翼手类动物4科6属15种.优势种是大蹄蝠、小菊头蝠、双色蹄蝠;新发现的稀有种类是印度假吸血蝠.     

根癌农杆菌介导的白腐丝状真菌——黄孢原毛平革菌的转化

利用农杆菌介导的方法成功地对黄孢原毛平革菌（Phanerochaete chrysosporium）进行了遗传转化。将含有潮霉素磷酸转移酶融合基因的双元质粒pCH61300转入根癌农杆菌（Agrobacterium tumefaciens）208中,然后用该转化菌分别感染黄孢原毛平革菌的分生孢子和原生质体,获得16株可能的转化子,经复筛,共获得6株潮霉素抗性水平为100μg/mL的稳定转化子,分生孢子和原生质体的转化频率没有明显差别。PCR检测结果显示,抗性基因已导入黄孢原毛平革菌细胞中;Southern杂交表明,TDNA以单拷贝形式整合到黄孢原毛平革菌基因组中。其中的一个转化子菌落形态与原野生型菌株相比有所不同,菌丝稀薄,分生孢子较少。利用分生孢子转化更为简便易行,无需特殊的设备和制备原生质体,此方法为深入开展该菌的遗传转化研究奠定了基础。     

Crop Yields, Internal Nutrient Efficiency, and Changes in Soil Properties in Rice–Wheat Rotations Under Non-Flooded Mulching Cultivation

A field experiment was conducted for 5 years to examine the effects of non-flooded mulching cultivation on crop yield, internal nutrient efficiency and soil properties in rice–wheat (R–W) rotations of the Chengdu Plain, southwest China. Compared with traditional flooding (TF), non-flooded plastic film mulching (PM) resulted in 12 and 11% higher average rice (Oryza sativa L.) yield and system productivity (combined rice and wheat yields), and the trends in rice and wheat (Triticum aestivum L.) yields under PM were stable over time. However, non-flooded wheat straw mulching (SM) decreased average rice yield by 11% compared with TF, although no significant difference in system productivity was found between SM and TF. Uptakes of N and K by rice under PM were higher than those under TF and SM, but internal nutrient efficiency was significantly lower (N) or similar (K) under PM compared to SM and TF. This implies that more N and K accumulated in rice straw under PM. After 5-year rice–wheat rotation, apparent P balances (112–160 kg ha⁻¹) were positive under all three cultivation systems. However, the K balances were negative under PM (−419 kg ha⁻¹) and TF (−90 kg ha⁻¹) compared with SM (45 kg ha⁻¹). This suggests that higher K inputs from fertilizer, straw or manure may be necessary, especially under PM. After five rice seasons and four wheat seasons, non-flooded mulching cultivation led to similar (PM) or higher (SM) soil organic carbon (SOC), total N (TN) and alkali hydrolyzable N (AH-N) in the top 0–5 and 5–12 cm layers compared with TF. SOC, TN, AH-N and Olsen-P (OP) in the sub-surface layer (12–24 cm) were significantly higher under PM or SM than under TF, indicating that rice under non-flooded mulching conditions may fail to make use of nutrients from the subsoil. Thus, the risk of decline in soil fertility under non-flooded mulching cultivation could be very low if input levels match crop requirements. Our data indicate that PM and SM may be alternative options for farmers using R–W rotations for enhancement or maintenance of system productivity and soil fertility.     

QTL analysis of the spring wheat “Chapio” identifies stable stripe rust resistance despite inter-continental genotype × environment interactions

Chapio is a spring wheat developed by CIMMYT in Mexico by a breeding program that focused on multigenic resistances to leaf rust and stripe rust. A population consisting of 277 recombinant inbred lines (RILs) was developed by crossing Chapio with Avocet. The RILs were genotyped with DArT markers (137 randomly selected RILs) and bulked segregant analysis conducted to supplement the map with informative SSR markers. The final map consisted of 264 markers. Phenotyping against stripe rust was conducted for three seasons in Toluca, Mexico and at three sites over two seasons (total of four environments) in Sichuan Province, China. Significant loci across the two inter-continental regions included Lr34/Yr18 on 7DS, Sr2/Yr30 on 3BS, and a QTL on 3D. There were significant genotype × environment interactions with resistance gene Yr31 on 2BS being effective in most of the Toluca environments; however, a late incursion of a virulent pathotype in 2009 rendered this gene ineffective. This locus also had no effect in China. Conversely, a 5BL locus was only effective in the Chinese environments. There were also complex additive interactions. In the Mexican environments, Yr31 suppressed the additive effect of Yr30 and the 3D locus, but not of Lr34/Yr18, while in China, the 3D and 5BL loci were generally not additive with each other, but were additive when combined with other loci. These results indicate the importance of maintaining diverse, multi-genic resistances as Chapio had stable inter-continental resistance despite the fact that there were QTLs that were not effective in either one or the other region.     

成都平原北部水稻土重金属含量状况及其潜在生态风险评价

为了解成都平原水稻土重金属含量状况和潜在的生态风险,选取成都平原北部水稻土典型区域为研究对象,采集了158个表层土壤样品,分析了土壤中pH值和Cd、Cu、As、Hg、Pb、Cr、Ni 7种重金属元素含量,以20世纪80年代测定的成都平原土壤重金属元素背景值为评价标准,采用Hakanson潜在生态危害指数法对研究区域的重金属潜在生态风险进行了评价。结果表明:研究区域水稻土Cd、Hg、Ni、Cu、Pb、Cr和As平均含量分别为0.709、0.187、32.08、34.12、31.52、82.13 mg/kg和7.25 mg/kg;Cd、Ni、Cu和Hg 4种重金属超过《土壤环境质量标准》(GB15618-1995) Ⅱ级标准值样本比例分别为87.34%、8.23%、3.80%和3.80%,Cd含量超标严重。7种重金属元素变异系数幅度为18.35%-49.03%,由大到小依次为Cd、Hg、Cu、As、Ni、Cr、Pb。75.32%的样本达到中度或较强重金属潜在生态风险,区域整体表现为中度潜在生态风险(RI平均值为198.65),Cd和Hg为高生态风险元素,对潜在生态风险贡献率分别为62.27%和20.78%,As、Pb、Cu、Ni、Cr为低生态风险元素;风险概率图显示城区周边和绵远河沿线的潜在生态风险等级较高。因此,成都平原水稻土农业生产中应采取一定的措施防控农产品Cd和Hg污染。     

Comparative study of four rice cultivars with different levels of cadmium tolerance

Cadmium (Cd) has been identified as a significant pollutant due to its high solubility in water and soil and high toxicity to plants and animals. Rice, as one of the most important food crops, is grown in soils with variable levels of Cd and therefore, is important to discriminate the Cd tolerance of different rice cultivars to determine their suitability for cultivation in Cd-contaminated soils. This study investigates the primary mechanisms employed by four rice cultivars in attaining Cd tolerance. HA63 cultivar reduces Cd uptake by increasing Fe absorption through activation of phytosiderophores. T3028 cultivar accumulates the highest level of Cd in leaves while also activating its reactive oxygen species (ROS) scavenging system, including antioxidant enzymes and phytochelatins. In some rice cultivars (such as HA63), a cyanide-resistant respiration mechanism, important in Cd detoxification, was also promoted under the Cd stress. In conclusion, different rice cultivars may adopt different biochemical strategies and respond with different efficiency to Cd stress.     

转基因植物中外源基因的沉默及应对策略

随着转基因技术在作物育种领域的应用,转基因植物中外源基因表达量低的现象较为普遍。导致外源基因表达量低的主要原因是基因沉默。外源基因沉默可分为转录水平的基因沉默和转录后水平的基因沉默。如何应对基因沉默,提高外源基因的表达量,是转基因技术发展亟待解决的问题。     

GA3和Spd对杜鹃开花期光合特性和抗氧化系统的影响

为探讨GA_3和Spd对杜鹃(Rhododendron simsii)开花花期和开花品质的影响,研究了外源GA_3和Spd对杜鹃开花期光合特性和抗氧化系统的变化。结果表明,外源GA_3对花期有显著的提前作用,Spd对花期有明显的延迟作用,但两者均使花期延长、花径增大且成花率提高。GA_3和Spd处理提高了花期叶片的光合色素含量和净光合速率(Pn)、气孔导度(Gs)和胞间CO_2浓度(Ci);GA_3处理提高了叶片的蒸腾速率(Tr),而Spd使叶片的Tr下降,两者均有效缓解了末花期叶绿素含量的下降。GA_3和Spd处理显著降低了花瓣MDA含量,提高了抗氧化酶SOD、POD和CAT活性,并减缓了末花期SOD的下降,有效延缓了衰老进程,延长花期。以1 600 mg L~(–1) GA_3和0.10 mmol L~(-1) Spd处理效果较好,能有效提高杜鹃花的观赏品质。     

Chinese white truffles shape the ectomycorrhizal microbial communities of Corylus avellana

Here, we investigated the influence of Chinese white truffle (Tuber panzhihuanense) symbioses on the microbial communities associated with Corylus avellana during the early development stage of symbiosis. The microbial communities associated with ectomycorrhizae, and associated with roots without T. panzhihuanense colonization, were determined via high-throughput sequencing of bacterial 16S rRNA genes and fungal ITS genes. Microbial community diversity was higher in the communities associated with the ectomycorrhizae than in the control treatment. Further, bacterial and fungal community structures were different in samples containing T. panzhihuanense in association with C. avellana compared to the control samples. In particular, the bacterial genera Rhizobium, Pedomicrobium, and Herbiconiux were more abundant in the ectomycorrhizae, in addition to the fungal genus Monographella. Moreover, there were clear differences in some physicochemical properties among the rhizosphere soils of the two treatments. Statistical analyses indicated that soil properties including exchangeable magnesium and exchangeable calcium prominently influenced microbial community structure. Lastly, inference of bacterial metabolic functions indicated that sugar and protein metabolism functions were significantly more enriched in the communities associated with the ectomycorrhizae from C. avellana mycorrhized with T. panzhihuanense compared to communities from roots of cultivated C. avellana without T. panzhihuanense. Taken together, these results highlight the interactions among ectomycorrhizal fungi, soil properties, and microbial communities that are associated with host plants and further our understanding of the ecology and cultivation of the economically important T. panzhihuanense truffles.

     

喜树碱的碱水法提取新工艺

本文根据喜树碱在一定条件下开环和闭环的可逆性,设计了喜树碱的水法提取工艺。