小麦籽粒抗性淀粉含量的分析

选用3个抗性淀粉含量较高的小麦品种和3个抗性淀粉含量较低的小麦品种按Griffing双列杂交设计配置成15个杂交组合, 以亲本及F₁为材料进行了小麦籽粒抗性淀粉含量的遗传规律分析, 旨在为高抗性淀粉含量且综合性状优良的新型保健小麦新品种(系)的选育提供理论依据。结果表明, 在6个小麦品种中, 安农90202和D68-20抗性淀粉含量的一般配合力较好, 能显著地提高杂种后代籽粒抗性淀粉含量。安农90202×04单28和06-5×D68-20组合的特殊配合力最好, 两者特殊配合力效应值显著地高于其他组合。小麦抗性淀粉含量的遗传符合加性-显性模型, 显性程度为超显性。控制抗性淀粉含量的增效等位基因表现为隐性, 且亲本中抗性淀粉含量的增减效等位基因的分布不平衡, 高抗性淀粉含量的亲本中隐性基因数量多于显性基因数量。实验中安农90202和04单28控制抗性淀粉含量的隐性基因较多,而宁春18和新春5号含有的显性基因数量较多。同时研究发现小麦抗性淀粉含量的狭义遗传力中等, 为36.49%。     

小麦外源DNA导入及转化的初步研究

采用改进的酚-RNA酶法从野生一粒、野生二粒、提莫菲维和波兰小麦幼苗中提取总DNA,用子房注射法和花粉管途径导入云南铁壳麦1号和湖北生产上应用的鄂恩1号小麦,发现D1代出现供体性状或新的变异性状,有些变异性能遗传到后代。     

外源DNA导入小麦引起遗传变异的验证

对由波兰小麦ＤＮＡ注射到普通小麦鄂恩１号子房获得的Ｄ５代稳定遗传变异２个转化株系的种子醇溶蛋白,进行单向和双向聚丙烯酰胺凝胶电泳分析,结果表明由外源ＤＮＡ导入获得转化株系的变异,与其种子醇溶蛋白电泳图谱出现供体的某些组分和缺少受体的某些组分相印证。     

干旱胁迫与小麦幼苗亚精胺代谢变化的关系

通过对亚精胺（spermidine,Spd）在抗旱性不同的小麦品种幼苗中的作用的研究,发现抗旱品种周麦18号在渗透胁迫处理时,其叶片中的Spd含量明显大于不抗旱的豫麦51号。用Spd合成的抑制剂甲基乙二醛-双（鸟嘌呤腙MGBG）处理周麦18号,则导致Spd含量下降和抗性的降低,外源Spd又可逆转MGBG对周麦18号在渗透胁迫下的伤害。外源Spd可以明显提高豫麦51号的叶片内Spd含量,并相应提高其抗性。以上结果表明,Spd可以提高小麦幼苗的抗渗透胁迫能力。     

小麦抗条锈病基因YrCN19的诊断检测和遗传分析

用小麦条锈病抗性基因YrCN19的诊断标记Xgwm410对19个小麦品种或品系进行PCR筛选,其中川农19、新抗5号、爱民5号和爱民6号扩增出与条锈病抗性基因YrCN19共分离的特征片断,其大小为391个碱基,而在其他的小麦品种或品系中未能检测到该片断。系谱分析和抗性鉴定结果表明川农19、新抗5号、爱民5号和爱民6号含有小麦条锈病基因YrCN19。抗性遗传分析发现小麦条锈病抗性在川农19,新抗5号和爱民5号中的遗传符合单个显性基因的遗传规律(3抗:1感);杂交组合烟辐188/爱民6号的抗性遗传也符合单个显性基因的遗传规律,而另外一些杂交组合(如R25/爱民6号,鲁955159/爱民6号和苏3110/爱民6号)中的抗性分离则符合两对基因互补的遗传规律(9抗:7感)。本研究揭示了小麦条锈病抗性基因YrCN19在不同遗传背景和杂交组合的抗性表达和分离有差异,从而加速YrCN19在小麦抗条锈育种中的开发与利用。     

小麦抗禾缢管蚜的生化研究

通过福林法、葸酮法、滴定法等分别测定了不同抗蚜性小麦品种植株中酚、糖含量及酸度。结果表明：小麦对禾缢管蚜尺Rhopalosiphum padi(Linnaeus)的抗性与小麦体内酚含量有关,抗性强的小麦其体内含酚量相对高,反之低。同时小麦抗性的强弱与体内糖含量,酸度亦有相关性。另外还测走了在不同抗性小麦品种上生长的蚜虫体内淀粉酶及羧酸酯酶的活性,结果表明在抗性强的小麦品种上生长的蚜虫体内淀粉酶,羧酸酯酶活性强,反之弱。     

水分胁迫对小麦幼苗叶片多胺含量的影响

水分胁迫下小麦幼苗叶片多胺含量变化的研究表明,聚乙二醇(PEG)的渗透胁迫明显提高了抗旱性强的周麦系列幼苗叶片游离态Put、Spd和Spm的含量和抗旱性弱的温麦6号的Put含量。外源Spd显著提高了水分胁迫下温麦6号的Spd的含量,对其抗性也有所改善。外源MGBG(Spd和Spm生物合成抑制剂)可提高水分胁迫下周麦12号Put的含量,但降低了Spd和Spm的含量和幼苗的抗性。     

小麦外源DNA导入引起变异的研究

1987年以来,作者采用改进的酚-RNA酶法从野生一粒、野生二粒、提莫菲维和波兰小麦幼苗中提取总DNA,并用子房注射法和花粉管途径导入云南铁壳麦1号及湖北生产上大面积应用的鄂恩1号。经观察发现,D_1代出现了供体性状或新的变异性状,有些变异性状能稳定遗传到D_3和D_4代。     

斯卑尔脱小麦的起源与遗传研究及其在普通小麦育种中的利用

斯卑尔脱小麦(Triticum spelta L.)是具有原始染色体组的带皮栽培种,其形态特征明显,是丰富小麦遗传变异、增强抗性等的重要基因资源.斯卑尔脱小麦与普通小麦间具有较大遗传差异,与普通小麦杂交具有很强的杂种优势.斯卑尔脱小麦氨基酸和微量元素含量较普通小麦含量高,且营养成分也更丰富.向普通小麦导入斯卑尔脱小麦的有益基因是改良普通小麦抗性和品质的有效途径之一.     

冬小麦灰分值的测定

用灼烧法对陇东学院农林科技学院育成的陇育1号、陇育2号、陇育3号、陇育4号、陇育5号、陇育6号小麦及其面粉进行灰分含量测定,研究小麦的灰分含量、小麦面粉中戊聚糖的含量及与灰分的关系,同时鉴定它们的品质。结果表明,陇育号小麦籽粒的灰分值含量一般在1.3%~1.5%,陇育号小麦面粉的灰分值0.4%~0.7%。根据小麦粉国家标准规定,陇育号小麦属于一、二等级小麦粉。陇育号小麦的戊聚糖含量与灰分之间有较好的正相关性。     

Evolvulus flavus sp. nov. (Convolvulaceae) from the Brazilian Caatinga

Evolvulus flavus is a new species of Convolvulaceae found in the semiarid region of Paraíba State, Brazil. It is characterized by flowers with a yellow corolla and 4‐locular ovary. Illustrations and taxonomic notes are presented. Only four individuals of this new species have been located, resulting in its classification as ‘Endangered’ (EN) in accordance with the IUCN criteria.     

Differences between rice and wheat in ribulose-1,5-bisphosphate regeneration capacity per unit of leaf-N content

The photosynthetic rates under saturating CO₂ conditions per unit of leaf‐N content were higher in wheat than in rice. This suggested that ribulose‐1,5‐bisphosphate (RuBP) regeneration capacity is greater in wheat. Therefore, the biochemical factor(s) for this difference were examined between rice and wheat. Soluble protein‐N, insoluble‐N, and trichloroacetic acid (TCA) soluble‐N contents were found not to differ between the two species. The activities of several Calvin cycle enzymes such as RuBP carboxylase, NADP‐glyceraldehyde‐3‐phosphate dehydrogenase, phosphoglycerate kinase and chloroplastic fructose‐1,6‐bisphosphatase (cpFBPase) activities per unit of leaf‐N content were all higher in wheat than in rice. Among them, cpFBPase activity was most highly correlated with CO₂‐saturated photosynthesis. The V_max activity of sucrose‐phosphate synthase (SPS) for UDP‐glucose was almost the same between the two species and its K_m value was a little lower in rice. Chlorophyll content and its a/b ratio did not differ. Cytochrome (Cyt) f content was greater in wheat, whereas coupling factor 1 content was greater in rice. Cyt f content was highly correlated with CO₂‐saturated photosynthesis, irrespective of the two species. The results thus suggested that higher RuBP regeneration capacity in wheat leaves is most closely related to a greater Cyt f content and that another candidate is cpFBPase.     

威岭栽培黑麦抗白粉病特性导入小麦的研究

威岭黑麦(Weiling rye)是一个高抗白粉病(Erysiphe gramininis f．sp．tritici)的中国矮杆栽培黑麦。以Weiling rye作为白粉病抗源,高感白粉病小麦栽培品种My8443为母本,从Weiling rye与小麦My8443远缘杂交的BC_2F_6后代中鉴定出一个新的小麦-黑麦易位系No．147,以实现威岭黑麦白粉病抗性向普通栽培小麦的转移。No．147及其亲本的抗白粉病特性通过苗期和成株期优势生理小种混合接种和室内单生理小种接种鉴定,改良的染色体C-分带和基因组原位杂交技术(GISH。Ge- nomic in situ hybridization)被用于鉴定小麦和黑麦的染色质,酸性聚丙烯酰胺凝胶电泳(APAGE)被用于鉴定黑麦醇溶蛋白1RS特异条带,11个黑麦种属特异性标记SCM(Secale cereale marker)引物被用于扩增分析黑麦特异性简单重复序列(SSR)。研究结果证实No．147是一个新的高抗白粉病的1BL/1RS小麦-黑麦染色体易位系,并对其产生的细胞学机制进行了分析。论文对中国栽培黑麦抗性基因资源的利用和该易位系在小麦遗传育种改良中的利用价值进行了讨论。     

Microchirita ruthiae sp. nov. (Gesneriaceae) from Peninsular Malaysia

A new species Microchirita ruthiae Rafidah (Gesneriaceae) from limestone in Kelantan, Peninsular Malaysia, is described and illustrated. This new species is characterized by having a branched stem, inflorescences with 1–4 flowers, the flowers with a white corolla (rarely faintly tinged with pale purple), glistening pale brown glandular hairs inside the throat, free anthers, and hairy capsules. Its conservation status following IUCN categories and criteria is assessed as ‘Endangered’ (EN).     

Analysis of Triticum boeoticum and Triticum urartu seed defensins: To the problem of the origin of polyploid wheat genomes

The origin of polyploid wheat genomes has been the subject of numerous studies and is the key problem in wheat phylogeny. Different diploid species have been supposed to donate genomes to tetraploid and hexaploid wheat species. To shed light on phylogenetic relationships between the presumable A genome donors and hexaploid wheat species we have applied a new approach: the comparison of defensins from diploid Triticum species, Triticum boeoticum Boiss. and Triticum urartu Thum. ex Gandil., with previously characterized Triticum kiharae defensins [T.I. Odintsova et al., Biochimie 89 (2007) 605-612]. Defensins were isolated by acidic extraction of seeds followed by three-step chromatographic separation. Isolated defensins were identified by molecular masses using MALDI-TOF mass spectrometry and N-terminal sequencing. For the first time, we have shown that T. urartu defensins are more similar to those of the hexaploid wheat than T. boeoticum defensins, although variation among samples collected in different regions of the world was revealed. Our results clearly demonstrate that T. urartu of the Asian origin contributed the A genome to polyploid wheat species.     

水分胁迫下不同进化型小麦抗氧化能力比较

以6种不同基因型小麦为试验材料,研究了水分胁迫下不同生长期小麦体内超氧化物歧化酶（SOD）活性以及超氧自由基（O2）含量变化,并分析了两者之间的相关关系。结果表明,水分胁迫下6种基因型小麦SOD活性及超氧自由基含量在拔节期和灌浆期均有不同程度的增加;栽培型品种SOD活性增幅高于野生型品种,超氧自由基增幅较低;同样,二粒小麦与一粒小麦相比,二粒小麦SOD活性增幅高于一粒小麦,超氧自由基增幅较低;但现代栽培小麦种表现不明显。结果说明,栽培型与野生型小麦相比,二粒小麦与一粒小麦相比,具有较强的抗氧化能力。     

Spiradiclis jingxiensis sp. nov. (Rubiaceae) from Guangxi,China

The new species Spiradiclis jingxiensis R. J. Wang is described here. It is similar to S. danxiashanensis with respect to its prostrate habit, small leaves, and terminal inflorescence with 1–3 salverform flowers, but is readily distinguished by pinkish flowers, and included stamens and stigmas in long‐ and short‐styled flowers. The conservation status of the new species was preliminarily assessed as ‘EN’ according to IUCN categories and criteria.     

Seed defensins from T. kiharae and related species: genome localization of defensin-encoding genes

Ten new defensins have been isolated from seeds of Triticum kiharae and related species of the Triticum and Aegilops genera by a combination of chromatographic procedures including affinity-, size-exclusion, and reversed-phase high-performance liquid chromatography. Nine were completely sequenced and shown to represent a family of closely related peptides with highly conserved amino acid sequences. Analysis of defensin compositions in diploid A-, B-, and D-genome donors to polyploid wheat allowed us for the first time to assign most defensin-encoding genes to particular hexaploid wheat genomes.     

Effect of microbial inoculants on the indigenous actinobacterial endophyte population in the roots of wheat as determined by terminal restriction fragment length polymorphism

The effect of single actinobacterial endophyte seed inoculants and a mixed microbial soil inoculant on the indigenous endophytic actinobacterial population in wheat roots was investigated by using the molecular technique terminal restriction fragment length polymorphism (T-RFLP). Wheat was cultivated either from seeds coated with the spores of single pure actinobacterial endophytes of Microbispora sp. strain EN2, Streptomyces sp. strain EN27, and Nocardioides albus EN46 or from untreated seeds sown in soil with and without a commercial mixed microbial soil inoculant. The endophytic actinobacterial population within the roots of 6-week-old wheat plants was assessed by T-RFLP. Colonization of the wheat roots by the inoculated actinobacterial endophytes was detected by T-RFLP, as were 28 to 42 indigenous actinobacterial genera present in the inoculated and uninoculated plants. The presence of the commercial mixed inoculant in the soil reduced the endophytic actinobacterial diversity from 40 genera to 21 genera and reduced the detectable root colonization by approximately half. The results indicate that the addition of a nonadapted microbial inoculum to the soil disrupted the natural actinobacterial endophyte population, reducing diversity and colonization levels. This was in contrast to the addition of a single actinobacterial endophyte to the wheat plant, where the increase in colonization level could be confirmed even though the indigenous endophyte population was not adversely affected.     

小麦T型细胞质雄性不育系、保持系蛋白质双向电泳比较研究

以小麦T型细胞质雄性不育系为材料,利用双向电泳技术,对苗期、分蘖期、拔节期和孕穗期叶片和花粉母细胞减数分裂期、单核小孢子期、二—三核小孢子期蛋白质变化作了分析。在细胞质雄性不育系小麦拔节期、孕穗期叶片中,有一个33KD/PI6.3蛋白组分存在,保持系中没有发现这个蛋白组分。在花粉败育的关键时期二—三核小孢子期,小麦细胞质雄性不育系有53KD/PI5.5、50KD/PI5.7、48KD/PI5.6和20KD/PI7.5四种蛋白组分存在,而保持系中也没有存在。小麦细胞质雄性不育系叶片和小孢子发育过程中存在的这五种特异蛋白可能参与育性调控,与细胞质雄性不育特性的形成有关。