小麦品种对土传小麦黄色花叶病毒病抗性遗传的初步研究

本试验通过杂交、回交和抗病性鉴定等方法,测定了14个组合的F_1代对土传小麦黄色花叶病毒病的抗性遗传。根据双亲正反杂交表现型一致的结果,可以确定控制小麦品种对该病毒病的抗性为细胞核遗传。通过对F_1、F_2、BC_1及BC_2各代群体抗病株和感病株分离比值的分析,初步确定有关土传小麦黄色花叶病毒病的抗性遗传可能受两对致病显性基因(S_1、S_2),和一对抑制基因(I)所控制,作者并对这一问题与前人工作作了比较和讨论。     

鲤CYR61基因的克隆、表达及系统进化树的构建

通过鲤(Cyprinus carpio)基因组序列与斑马鱼(Danio rerio)CYR61基因编码区全序列的比对得到了CYR61 A、CYR61 B和CYR61 C共3条序列。分别克隆、测序得到其开放阅读框(Open Reading Frame,ORF)分别是1 158 bp、1 053 bp、1 107 bp,CYR61 A和CYR61 C得到完整编码区,都是由5个外显子和4个内含子构成,分别编码385、368个氨基酸,其理论等电点值分别是7.83、8.54,分子量(Mw值)分别为42.55 ku、40.83 ku。鲤3个CYR61基因具有高度同源性,并且均含IB、vWC、TSP1、CT 4个模块。分子系统学分析表明鲤CYR61基因与其他物种CYR61基因具有高度同源性,且CYR61 C与其他高等物种的CYR61同源性更高,利用MEGA 5.0计算出CYR61 A、CYR61 B和CYR61 C的分化时间早于鲤和斑马鱼的物种分化。CYR61 C在13个组织中均有表达,在卵巢中表达最高,肠、脑、鳃次之,在其他组织中表达较低且在心脏中表达最低。CYR61 A在精巢、肠、鳃中表达较高。CYR61 B在精巢和脑中表达最高,肠、肌肉、卵巢次之。实时荧光定量PCR分析CYR61 3个复制在鲤胚胎发育时期的表达,都是在0 h相对表达量最高,显著降低至18 h或24 h,随后逐渐升高并在6 d时下降。     

~(14)C示踪研究不同小麦品种开花、灌浆期的光合效率及同化物的运转与分配

应用~(14)C示踪技术测定三个籽粒饱满度不同的小麦品种,结果表明:籽粒饱满度与品种的净光合率、光合持续期和同化物在籽粒中的分配率有关;光合作用后30分钟测定,~(14)C同化物的分配,叶片最高,叶鞘其次,麦穗再次,茎中最低;开花期~(14)C同化物在成熟麦穗中的分配,约占引入量的25—32％,灌浆期~(14)C同化物在成熟麦穗中的分配,对籽粒饱满的两个品种,占引入量的50％以上,而籽粒不饱满的品种,分配率还不到30％。     

水稻半纤维素支链合酶基因GT61家族的结构特征和组织表达分析

从生物信息学和基因表达的角度,鉴定OsGT61家族成员的结构特征和组织表达特性。结果表明,OsGT61家族含有25个成员,分为3个亚类。A、B和C亚类分别含有19、3和3个成员,其基因的外显子数介于1~7个。其蛋白质大小为49.1~73.8ku,pI为5.4~10.4。该家族蛋白质的C端motif较为保守。而且,它们含有Ser/Thr激酶的磷酸化位点分别为9~29个和3~13个,Tyr激酶的磷酸化位点小于7个。但是,该家族成员的糖基化位点相对较少,16个成员存在1~4个O-糖基化位点,3个蛋白存在1~2个N-糖基化位点。基因表达芯片聚类分析和半定量RT-PCR检测表明,OsGT61基因家族主要成员在不同组织中表达水平存在明显差异。这些结果暗示OsGT61家族基因在水稻不同组织中细胞壁半纤维素生物合成中发挥不同作用。     

Prolonged elevated atmospheric CO2 does not affect decomposition of plant material

Prolonged elevated atmospheric CO₂ might alter decomposition. In a 90-day incubation study, we determined the long-term (9 years) impact of elevated CO₂ on N mineralization of Lolium perenne and Trifolium repens plant material grown at ambient and elevated CO₂ and low- and high-¹⁵N fertilizer additions. No significant differences were observed in recovery rates between any of the treatments, except an N addition effect was observed for L. perenne (0.4 versus 0.5% day⁻¹ in high versus low N). The results suggest that elevated CO₂ did not change plant N mineralization in any of the soils, because of a surplus of available N in the fertilized and leguminous systems, and because of insignificant plant responses to elevated CO₂ in the low soil N availability systems.     

CLINICAL,DIAGNOSTIC, AND PATHOLOGICAL FEATURES OF 2 CASES OF METASTATIC IRIDOPHOROMA IN A VEILED CHAMELEON (CHAMAELEO CALYPTRATUS) AND A RED-BARRED DRAGON (CTENOPHORUS VADNAPPA)

Iridophores are iridescent cutaneous pigment cells found in reptiles, fish, and amphibians. Neoplasms of iridophores are rarely reported, and little is known about their behaviour, metastatic potential, and prognostic indicators. This paper reports details of the clinical course and pathological findings of metastatic iridophoroma in a veiled chameleon (Chamaeleo calyptratus) and red-barred dragon (Ctenophorus vadnappa). The veiled chameleon presented with a subcutaneous mass on the right lateral elbow and was diagnosed as an iridophoroma on fine needle aspiration. It was otherwise clinically normal. Within 35 days of excision, multiple secondary skin masses developed which were often non-pigmented and required microscopic examination to identify them as iridophoroma metastases. There were in total 54 days between the first detection of the primary mass and end stage, extensive cutaneous and visceral metastatic disease, and there had been no detectable primary mass during routine clinical examination 128 days prior to death. The red-barred dragon presented with a white sub-mandibular mass. While undergoing an excisional biopsy the animal expired, post-mortem examination revealed a cutaneous malignant iridophoroma with tumour cell clusters seen in pulmonary arterial vessels, suggesting that surgical handling of iridophoroma could precipitate the release of circulating tumour cell clusters. This is the first iridophoroma described in a red-barred dragon and the second report of a malignant iridophoroma in a veiled chameleon. Timely detection and careful excision of lizard iridophoroma may be an important factor in clinical outcome.     

小麦条锈病菌新菌系G22-9(CYR34)和G22-14流行趋势预测

为预测小麦条锈病菌新菌系G22-9(CYR34)和G22-14的未来流行趋势,科学指导小麦抗病育种及条锈病治理,采用常规鉴定法于2009—2016年对甘肃省2 330份小麦条锈病菌标样进行了生理小种鉴定及消长动态监测,并对G22-9(CYR34)和G22-14的致病性及寄生适合度进行了测定。结果发现:新菌系G22-9(CYR34)和G22-14在甘肃省的出现频率加快,已从2009年的0分别上升到2016年的34.85%和6.43%,其中G22-9(CYR34)已发展为甘肃省第1位流行生理小种。与主流生理小种CYR32和CYR33相比较,G22-9(CYR34)和G22-14具有毒性谱宽、致病力强、寄生适合度高、哺育品种多等特点。建议在甘肃省特别是小麦条锈病常发易变区的陇南麦区,针对新菌系的出现,及时调整小麦品种布局及育种目标,以持续控制条锈病的发生流行。     

凡纳滨对虾内质网膜转运通道蛋白基因Sec61γ的克隆及表达分析

以生长性状为指标分离凡纳滨对虾Litopenaeus vannamei家系的肌肉组织,构建凡纳滨对虾生长性状差减cDNA文库,进行斑点杂交筛选获得内质网膜转运通道蛋白基因Sec61γ基因,克隆获得cDNA全长编码序列及部分非编码序列。序列包含270 bp的开放阅读框,推测编码的蛋白质为89个氨基酸,预测的相对分子质量为10 300,理论等电点为10.58。通过荧光定量PCR的方法研究了Sec61γ基因在对虾不同组织和不同生长期肌肉组织中的表达情况,结果表明：Sec61γ基因在对虾的血液以及心脏、肝胰腺、肌肉、胃、肠、眼柄等器官或组织中都有表达,其中在肌肉组织中表达量最高,在肠中表达量最低;在对虾不同生长期肌肉中的表达量各不相同,在10日龄的对虾肌肉组织中表达量最高,为45日龄的对虾肌肉组织中表达量的27.6倍。