贵州西部‘红阳’猕猴桃溃疡病与温湿气象条件的联系

为了研究温湿气候变化对‘红阳’猕猴桃溃疡病发生的影响,以‘红阳’猕猴桃为试材,基于2013—2018年贵州猕猴桃主要种植区的水城县猴场、米箩、勺米、六枝特区郎岱、盘州市普古共5个试验区3—4月溃疡病监测资料以及同期温度、湿度、持续降雨日数资料,运用数理统计方法,分析溃疡病发生和流行与温度、湿度、持续降雨日数的联系。结果表明：‘红阳’猕猴桃溃疡病始发的气象条件为持续4天及以上有降水天气（日降水量≥0.1 mm）出现,且日平均温度≤15.0℃、日平均相对湿度≥80%,同时溃疡病始发之后继续维持1天及以上的低温阴雨高湿天气;溃疡病流行的气象条件为持续4天及以上有降水天气（日降水量≥0.1 mm）出现,且日平均温度≤18.0℃、日平均相对湿度≥80%,同时溃疡病流行之后继续维持1天及以上的低温阴雨高湿天气。贵州西部‘红阳’猕猴桃溃疡病的发生、流行对温湿变化有较好的响应。     

红肉猕猴桃新品系SF-HY-0201遗传特性

以红肉猕猴桃品种"红阳"为对照,通过生物学特性调查、体细胞染色体数目的观察和ISSR标记分析,对红肉猕猴桃新品系SF-HY-0201形态水平、细胞水平和分子水平的遗传特性进行了检测和比较。结果表明,SF-HY-0201和红阳的花、叶、果等生物学特性均存在显著差异;SF-HY-0201和红阳的染色体均为2n=2x=58,都是二倍体;7对ISSR引物共扩增出56条带,其中多态性条带27条,达48.21%,各引物扩增的多态性条带数在1~8条之间,能揭示红阳与SF-HY-0201间的遗传差异,为今后猕猴桃育种和杂交亲本的选择提供依据。     

利用ISSR分子标记分析29个风信子品种的遗传多样性

现代栽培的所有园艺风信子都是由原种风信子(Hyacinth orientalis)培育驯化而来,其遗传基础相对较窄,但经过几个世纪栽培选育,已经发生很大变化。为研究风信子品种之间的遗传关系,本研究利用12条引物对29个风信子品种进行ISSR分子标记研究,扩增获得109条谱带,多态性条带有103条,占条带总数的94.5%,表明风信子具有较高的遗传多样性。29个风信子品种的遗传距离范围为0.018 5~0.820 1,平均遗传距离为0.449 8。其中‘Atlantic’与‘Gipsy Queen’遗传距离最大为0.820 1,亲缘关系最远;‘Blue star’与‘Delf Blue’遗传距离最小,两品种之间相似度较大,亲缘关系最近。使用软件NTSYS-pc(2.10e版)获得UPGMA聚类树形图,以相似系数0.635为阈值,29个风信子品种可聚为两大类。聚类分析发现相同色系的品种几乎聚为一类,说明同色系风信子品种亲缘关系较近。因此,在杂交育种时可选择不同花色的品种作亲本,进行新品种的选育。     

宁夏粳稻种质资源表型性状遗传多样性分析

为了解宁夏水稻种质资源遗传多样性水平,对宁夏60份粳稻种质资源材料的16个表型性状进行遗传多样性分析。结果表明,60份宁夏水稻种质资源材料16个表型性状间存在极显著的遗传差异,其中株高、每穗总粒数、每穗实粒数、经济系数、结实率、秆长这6个表型性状的变异幅度大,方差和标准差较高,具有较大的离散程度;每穗总粒数、每穗实粒数、着粒密度、单株穗数、单穗粒重的变异系数均在14%以上,F测验表明16个表型性状的差异都达到了极显著水平;遗传相关分析表明,不同表型性状间存在显著、极显著相关关系,有些性状间为正相关关系,而有些性状间则为负相关关系,各表型性状间呈复杂的相互关系;遗传多样性分析表明,表型遗传多样性指数变幅为1.644~2.092,平均为1.957;以卡方距离按UPGMA法聚类,在遗传相关系数为0.11处可分为8类,其中‘杨和白皮稻’、‘抚105’、‘田丰302’和‘花86’各为一类,其他引进和宁夏自育的水稻品种分别聚在第Ⅳ、Ⅴ、Ⅵ、Ⅷ类,而57%的种质资源材料都聚在了第Ⅵ类,并且第Ⅳ、Ⅴ、Ⅵ、Ⅶ、Ⅷ类在相似系数为0.18处可聚成一大类,亲缘关系很近。‘杨和白皮稻’是宁夏的1个地方品种,与其他种质间亲缘关系最远。研究表明,宁夏粳稻种质资源材料间遗传差异较小,遗传背景比较单一,亲缘关系较近。     

‘Hort 16A’猕猴桃自由授粉后代AFLP分析

‘Hort 16A’猕猴桃是继‘Hayward’之后的第二代猕猴桃优良品种,备受消费者青睐。其后代遗传了母本大多数的优良品质,但其遗传分化及后代优株分子标记的研究还未见相关报道。本研究将24株具有优良性状的‘Hort 16A’猕猴桃自由授粉后代,通过优化酶切、连接、预扩增、选择性扩增等步骤建立AFLP反应体系,并利用Popgene和NTSYS分别对遗传多样性参数和个体聚类进行分析。结果表明,筛选出的5对多态性较高的选择性扩增引物,共扩增出426个AFLP标记,多态性标记424个,多态性标记百分比达到99.53%。不同优良株系在M-CAC/E-AGC引物对上均有特异性位点,这些特异位点用于申报优良品种保护。总基因多样度(Ht)为0.300 0,居群内基因多样度(Hs)为0.289 8,遗传分化系数(Gst)为0.030 2,基因流(Nm)为14.101 8。遗传分化系数远小于0.15,而基因流远大于4。在通过NTSYS软件聚类后,在遗传相似系数为0.51时,将24个个体分为2个大支。本研究的结果多态性比例很高,对样品的区分率达到100%,为猕猴桃AFLP分析检测提供了很大应用和指导借鉴价值。     

‘砀山酥梨’芽变‘97-05-9’的RAPD分析

利用RAPD分子标记技术对37份梨种质资源进行了遗传亲缘关系及分类研究。从80个随机引物中筛选出27个引物进行扩增,应用SPSS11.0软件进行聚类分析。聚类分析结果表明:不同梨品种之间存在明显的遗传差异,‘砀山酥梨’与营养系变异‘97-05-9’具有很近的亲缘关系,归为一类。且‘砀山酥梨’与其营养系变异‘97-05-9’有14个引物扩增出18条特异性条带,变异位点较多。     

不同基因型猕猴桃果实抗坏血酸代谢基因差异变化

抗坏血酸(AsA)即维生素C,是维持人类生长发育所必需的化合物,为了探明不同基因型猕猴桃果实As A水平差异机制,本实验以‘红阳’和‘海沃德’猕猴桃果实为材料,测定其生长发育过程中As A和总抗坏血酸(T-AsA)含量,并分析了As A代谢过程相关酶基因的表达水平。结果表明,两个品种As A和T-AsA含量均呈现不断下降的变化趋势,且在整个生长过程中,‘红阳’果实As A和T-AsA含量显著高于‘海沃德’果实。荧光定量PCR结果表明,果实As A的积累是合成、循环和降解途径协同作用的结果,并证实了L-半乳糖途径是猕猴桃果实As A合成的主要途径,L-半乳糖途径的大多数基因均参与调控As A的合成,其中AdPMI、AdPMM、AdGME2和AdGalLDH基因在‘红阳’果实中具有较高的转录水平,推测这4个基因是猕猴桃种间As A水平存在差异的重要因素。此外,我们还发现循环途径的AdMDHAR2、AdDHAR和AdGR基因以及降解途径的AdAPX基因,同样在两品种间有差异表达,因此As A的循环再生也可能是引起‘红阳’果实高As A水平的重要原因。     

小麦K-CMS保持系主要农艺性状的系统聚类分析

通过对21 个小麦K-CMS保持系品种的农艺性状进行调查,旨在分析这些品种的遗传多样性。以2 年田间试验得到的株高、穗长、小穗数、穗下节长、穗粒草重、穗粒数、穗粒重、旗叶长等农艺性状为依据,计算21 个品种间遗传距离,采用类平均分析法(UPGMA)对供试材料进行聚类分析。结果表明：供试的21 个品种共划分为6 个类群,Ⅰ类为‘大作1 号’、‘国育101’、‘濮麦6311’、‘中育1211’、‘焦麦268’、‘长育918’、‘泛麦526’;Ⅱ类为‘锦科2 号’、‘安农12’;Ⅲ类为‘经科168’;Ⅳ类为‘偃农27’、‘农科668’;Ⅴ类为‘存麦15’、‘上麦1号’、‘聊麦18’、‘囤麦127’、‘科林04177’、‘光泰54’、‘郑麦1290’、‘耕麦787’;Ⅵ类为‘昌麦9 号’。划分结果与系谱分析基本一致,并把系谱来源不清的品种划分到相应的杂种优势群。小麦K-CMS保持系品种形状检测是研究保持系品种间遗传差异的一种方法,可为小麦“三系”选育提供初步的理论依据。     

基于nrDNA-ITS序列的10种枸杞属植物亲缘关系研究

以10种枸杞属植物为材料,利用nrDNA-ITS序列,探讨其遗传多样性及亲缘关系。采用改进CTAB法提取枸杞叶片基因组DNA,利用合成的ITS4和ITS5为引物对其DNA中的nrDNA-ITS区进行扩增、对目的片段测序,并对测序结果进行聚类分析。测序结果表明,10种枸杞属植物ITS的长度为582~656 bp,保守位点(C)560个,变异位点(V)95个,其中简约信息位点(Pi)70个,单核苷酸变异位点(S) 25个;5.8S序列的长度均为154 bp,保守位点(C)136个,变异位点(V)18个,其中简约信息位点(Pi)12个,单核苷酸变异位点(S)6个。10条序列聚类图明显地分为2大类5个小组,‘0901’与‘蒙杞1号’处于同一分支,亲缘关系最近,‘宁杞3号’和‘宁杞7号’为同一分支,亲缘关系最近,‘宁杞5号’和青海诺木洪黑果枸杞单独为一分支,与其他几个枸杞品种的亲缘关系最远。10条枸杞属植物的ITS序列已上传至NCBI,登录号为KJ189761~KJ189770。本研究测序和分析了10种枸杞属植物的ITS序列,聚类结果表明了它们之间的亲缘关系与差异,为枸杞遗传多样性和系统发育研究奠定了基础。     

基于DNA序列的‘和田’玫瑰遗传背景分析研究

‘和田’玫瑰为国内主栽的玫瑰品种之一，其遗传背景不明确不利于产品开发和推广应用。本研究选择‘和田’玫瑰的疑似近源种，采用ITS和atpB-rbcL序列分析的方法，通过构建系统进化树分析它们的亲缘关系，明确其遗传背景。结果显示，ITS序列多态性较高，尤其是ITS2序列能够获得更多的遗传信息，基于ITS2序列，‘和田’玫瑰和法国蔷薇聚为一个小分支，说明其亲缘关系较近。atpB-rbcL序列在被测植物材料间的多态性比较低，但可以反映母本信息，‘和田’玫瑰与法国蔷薇、百叶蔷薇、腓尼基蔷薇和玫瑰在一个分支内。结合ITS的聚类结果，推测法国蔷薇为‘和田’玫瑰的母本，与大马士革蔷薇有共同亲本起源。     

Inheritance of resistance to Pseudomonas syringae pv. actinidiae and genetic correlations with fruit characters in a diploid Actinidia chinensis (kiwifruit) population

Bacterial canker of kiwifruit, caused by a virulent strain of Pseudomonas syringae pv. actinidiae (Psa), has resulted in serious damage to kiwifruit industry worldwide. The variability and inheritance of resistance to Psa and fruit characters in a disconnected factorial mating population of diploid Actinidia chinensis Planch were investigated. Significant variation in all characters was found, and this appeared to be under polygenic control. Results indicated the extent and nature of genetic variation in Psa resistance available in our breeding gene pool. Estimates of narrow-sense heritability were moderate-high to high for Psa resistance, fruit weight, dry matter content (DM) and soluble solids contents (SSC), but low for fruit number per vine. The moderate-high heritability for Psa resistance indicated a genetic control of the observed variation, and selection for Psa resistance could be possible. Psa resistance had a high negative genetic correlation with fruit number per vine, but a moderate positive correlation with fruit weight, DM and SSC. The results implied that yield penalty of Psa resistance might exist in kiwifruit. Thus, selection strategies based on Psa resistance need to take account of its negative correlation with fruit number per vine. Male and female parents useful for improving Psa resistance and fruit characters simultaneously were identified. Two full-sib families were outstanding, as they combined high degrees of resistance to Psa with high yield components and reasonable amounts of DM and SSC.     

Postharvest performance of the yellow-fleshed ‘Hort16A’ kiwifruit in relation to fruit maturation

Postharvest performance of fruit is dependent on the maturity or physiological state of the fruit at harvest in conjunction with the postharvest management applied. For yellow-fleshed kiwifruit, the flesh colour is a significant quality attribute, and for ‘Hort16A’, flesh colour has been used for timing harvest. Variability in the postharvest performance of ‘Hort16A’ kiwifruit suggests that flesh colour alone is not as strongly indicative of postharvest performance as soluble solids content (SSC) was found to be for ‘Hayward’ kiwifruit 30 years ago. The postharvest performance of ‘Hort16A’ kiwifruit, assessed as the fruit firmness and chilling injury expression during storage, has been associated with a range of fruit characteristics: flesh colour, SSC, firmness, seed colour, fresh weight, dry matter, starch and soluble carbohydrates measured at harvest throughout maturation. The changing responses of the fruit SSC to temperature, and softening to ethylene, have also been determined. The data illustrate the complex nature of ‘Hort16A’ fruit maturation, even when looking only at simple, easy-to-measure fruit attributes. While a yellow flesh colour is a commercial necessity for ‘Hort16A’ kiwifruit, flesh colour is not a robust indicator of postharvest performance and is not tightly linked to SSC or firmness. Changes in the capacity of fruit to respond to temperature or ethylene are not reflected in on-vine changes. Softening in storage is strongly linked to the softening rate occurring on the vine at the time of harvest. Any association between at-harvest characteristics and chilling susceptibility is less clear, and chilling tolerance appears more associated with the completion of growth and carbohydrate accumulation than with increased soluble solids accumulation rates as in ‘Hayward’. Approaches to extend the understanding of the link between maturation, harvest indices and postharvest performance are discussed.     

多酚、黄酮及甾醇与番茄抗晚疫病关系

以对番茄晚疫病抗性较强的番茄品种‘25-1’和易感染番茄晚疫病的品种‘京乐502’为试材,通过人工接种病原的方法,研究多酚、黄酮及甾醇与番茄品种晚疫病抗性之间的关系。结果表明：（1）健康叶多酚类和甾醇类含量在2 个品种间无显著差异;黄酮类含量抗病品种‘25-1’显著高于感病品种‘京乐502’。（2）接种后,多酚类和黄酮类含量在2 个品种中均呈先增后减的趋势。峰值出现时间‘京乐502’晚于‘25-1’。总甾醇含量与番茄晚疫病抗性密切相关。接种晚疫病病原后,2 个品种中总甾醇含量均都呈下降趋势。随着病情的发展,感病品种‘京乐502’的总甾醇含量迅速下降,抗病品种‘25-1’下降较为缓慢。     

黔东南州红心猕猴桃叶尖干枯病病原鉴定

为减少黔东南州的红心猕猴桃病害危害、保证产品质量,对产区内的新病害发生情况进行调查研究及病原鉴定。采用组织分离法对病叶进行病原菌分离,使用核糖体rDNA-ITS(Internal transcribed spacer)区序列分析法进行DNA测序,使用MEGA 4.0软件构建分子进化树,结合形态学观察对致病菌进行分类鉴定。结果表明,由病原菌高粱附球菌(Epicoccum sorghinum)导致的一种新病害——叶尖干枯病对红心猕猴桃有严重危害。     

New sources of resistance for stripe rust in barley

Eight spring barley accessions from the gene bank in Gatersleben, Germany, and 10 cultivars were tested for stripe rust resistance. Tests were performed at the seedling stage in the growth chamber and as adult plants in the field. All accessions and six cultivars were scored as resistant against race 24 under all test conditions, with very few plants as exceptions, while the susceptible control cultivars ‘Karat’ and ‘Certina’, and four other cultivars were attacked in all cases. Differences between accessions and between cultivars were detected after infection with isolates from ‘Trumpf’ and ‘Bigo’ (seedling tests only). Infection structures within seedling leaves without pustules and for the first time within leaves of adult plants from the field were analysed by fluorescence microscopy. With this method additional genetic Differences in the resistance reaction could be detected which could not to be seen in the resistance test. Crosses between the accessions and the susceptible cultivar ‘Karat’ led to segregating F₂ progenies. The percentage of resistant plants varied between the accessions. This also indicates a different genetic basis of resistance in the accessions. The infection structures observed by fluorescence microscopy stopped earlier in leaves of the two accessions HOR 8979 and HOR 8991 than in leaves of other accessions in all the tests. These accessions were the only ones with more than 50% resistant plants in all F₂ tests. In general, the accessions from the gene bank can be used as new resistance sources against stripe rust.     

Inheritance of salt tolerance in rice

Summary The genetic behavior of salt tolerance was studied in artificially salinized conditions at the International Rice Research Institute.Divergent selection, carried out at a salinity level where the ECe was 15.2 mmhos/cm at 25 C in F₃ lines from two crosses confirmed the effects of salt tolerance on F₄ progeny with realized heritability values of 0.39 and 0.62, respectively.In a cross between two tolerant cultivars there was clear over-dominance for tolerance, despite the high environmental fluctuation which resulted in a low genetic response as indicated by a low but significant repeatability of 0.20–0.25, and many progeny lines more tolerant than the parents were recovered. The superior tolerance of these progenies compared to the parents was confirmed subsequently at 3 different salt levels. In the same experiment a cross between tolerant and susceptible cultivars produced some progeny of comparable tolerance with tolerant sources.In a 6×6 diallel cross experiment with two tolerant, moderate, and susceptible varieties each, both general and specific combining ability were significant.The findings indicate the possibility of breeding rices more tolerant than existing tolerant cultivars through cumulative crosses of tolerant cultivars. Further improvement can be attained by crossing highly tolerant lines with donors of good agronomic traits and pest and disease resistance.     

四川省丁香假单胞猕猴桃致病变种的遗传多样性分析

为明确四川省猕猴桃溃疡病菌丁香假单胞菌猕猴桃致病变种(Pseudomonas syringae pv. actinidiae,Psa)的遗传多样性及群组划分与地理来源的相关性。以四川省不同地理来源的40个Psa菌株为研究试材,用rep-PCR技术进行分子标记,NTSYS软件分析UPGMA聚类。3对rep-PCR检测引物(REP、ERIC和BOX)共获得42个位点,其中38个为多态位点,占90.5%。UPGMA聚类结果显示,以相似系数为0.70阀值时,40个Psa菌株被分为2个类群(Ⅰ、Ⅱ),其中85.0%的菌株属于第Ⅱ类群;在相似性系数为0.80时,第Ⅰ类又可分为2个亚类(Ⅰ-1、Ⅰ-2),第Ⅱ类则分为5个亚类(Ⅱ-1、Ⅱ-2、Ⅱ-3、Ⅱ-4、Ⅱ-5),菌株无明显的采集地聚类。以上结果表明,四川省各地区的猕猴桃溃疡病菌菌株具有较高的遗传多样性,但其遗传变异与菌株地理来源无明显相关性。     

Classification of Brazilian wheat cultivars for aluminium toxicity in acid soils

Aluminium (Al) toxicity is an important limiting factor for wheat Triticum aestivum L. adaptation to acid soils in different regions of Brazil. The purpose of this research was to classify the reaction of recommended wheat cultivars in Brazil in relation to Al toxicity. Seventy-five cultivars were tested from 3 to 15 years under field conditions from 1980 to 1995 in Passo Fundo, Brazil. Soils with pH between 4.2 and 4.9 contained from 2.50 to 4.27 cmol Al/1. The resistance to aluminium in acid soil was evaluated visually before heading time in some years and at maturity in all years in three replications, using a score ranging from 0.5 (highly resistant) to 5 (highly susceptible). Using the over-years mean index, 19 cultivars were classified as resistant, 33 as moderately resistant, 17 as moderately susceptible, and six as susceptible. The cultivars ‘BH 1146’, ‘Embrapa 15’, ‘Embrapa 24’, ‘Embrapa 49’, ‘IAC 5-Maringá’, ‘IAC 18-Xavantes’, ‘IAC 27-Pantaneiro’, ‘IAPAR 46’, ‘IAPAR 53’, ‘RS 8-Westphalen’, Trigo BR 15’, ‘Trigo BR 20-Guató’, ‘Trigo BR 25’, ‘Trigo BR 35’, and ‘Trigo BR 41-Ofaié’ were the most Al resistant of the 75 tested. It is highly probable that all Brazihan Altolerant cultivars have a major gene known to be on the long arm of chromosome 4D. Aluminium tolerance was traced by pedigree analysis to a small number of landraces introduced and grown in Brazil in the early twentieth century. Breeding for resistance to Al is required because soil amehoration by liming is effective only in the upper root zone and susceptible or moderately susceptible cultivars do not develop extensive root systems and suffer under drought or heat stress.     

Microstructural characterisation of commercial kiwifruit cultivars using X-ray micro computed tomography

The skin is the physical barrier between the fruit and the environment in which it develops. Environmental conditions during fruit development have a large influence on fruit quality, both at the time of harvest and during subsequent storage. It is hypothesised that some features of the skin and sub-epidermal tissues could provide information about the past growing conditions to which the fruit was exposed and therefore be of predictive value for storage quality. In this study, five commercial kiwifruit cultivars (‘Hayward’, ‘Hort16A’, ‘G3’, ‘G9’ and ‘G14’) were studied, and ‘Hayward’ fruit were manipulated during growth with different cultural practices. After harvest at horticultural maturity, X-ray micro computed tomography (μCT) was used to investigate features of the skin and the immediate parenchyma tissue. Despite orchard management practices (crop load and girdling) being observed to effect macro fruit quality parameters (mass, firmness, SSC, and DM), differences in microstructure (e.g. porosity) caused by these practices were not observed. However, porosity and pore size were found to be highly variable between cultivars. The thickness of dense sub-epidermal tissue could be readily measured and the 3-D distribution of raphide bundles was visible as high density particles distributed within the parenchyma. Overall, μCT was found to be a powerful technique to explore fruit epidermal and sub-epidermal structures in three dimensions at a micro level. However, the length of time required for data capture and analysis and the large number of samples required to overcome natural variation within horticultural products need to be considered. Future work may define the impact of differences in porosity or sub-epidermal anatomy on kiwifruit physiology (e.g. firmness change or sensitivity to low oxygen storage atmospheres). With this information, μCT could be used as a screening tool during plant breeding, or to determine the response to agronomic treatments, without conducting lengthy storage trials.     

Changes in volatile production and sensory quality of kiwifruit during fruit maturation in Actinidia deliciosa ‘Hayward’ and A. chinensis ‘Hort16A’

Although volatiles have been previously studied in kiwifruit (Actinidia spp.), there has been no co-ordinated study of volatile release and softening through the full edible period. In this report, the two most important commercial cultivars A. deliciosa ‘Hayward’ and A. chinensis ‘Hort16A’ were evaluated for volatiles released at different ripening stages corresponding to their typical commercial shelf life, and compared to the sensory quality assessed by a trained taste panel. Gas chromatography–mass spectrometry data indicated that large amounts of straight-chain aldehydes and esters were the dominant volatiles in the two cultivars. In particular, butanoates, the main fruity esters in both fruit, significantly increased during ripening and an extremely high level of butanoates was found in the over-ripe fruit. Sensory results indicated that with fruit softening, some of the changes in volatile content could explain changes in fruit flavor detected by a trained panel, and differences in characteristic flavor of the two cultivars. The results have implications for fruit sample handling and volatile assessment.