小麦品种面粉粘度性状的品质分析

研究了2个地区21个小麦品种面粉的快速粘度仪参数。结果表明,不同地区不同品种对淀粉快速粘度仪参数均有一定的影响。峰值粘度主要受基因型与环境互作的影响,衰减度相对受基因型的影响较大,其他性状受环境影响比较大。而弱筋小麦品种的淀粉糊化特性指标的环境变异明显高于强筋、中筋品种,说明弱筋小麦淀粉糊化特性受环境影响的程度较大。     

淀粉和变性淀粉糊化特性的研究

用布拉班德淀粉粘度仪研究了不同的原淀粉和变性淀粉的糊化特性,用成糊温度(PT),热糊粘度(H)、冷糊粘度(C)、和各种粘度差,即破损值或崩解值(P-H)、回值(C-P)、总回值或稠度(C-H)、相对破损值(P-H/C-H)等来表示.这些特性在不同淀粉之间存在明显的差异.淀粉中直链淀粉的含量对淀粉的糊化和老化倾向影响很大.变性处理可以改变原淀粉的糊化特性,例如酯化(或醚化)能使玉米淀粉的成糊温度降低,老化倾向减小,粘度稳定性变差,而交联则使其粘度稳定性增强,能够抵抗酸和剪切力的影响.     

小麦品种淀粉糊化特性研究

利用快速粘度仪(RVA)分析了山西省2008～2009年度冬小麦新品种区试和生产试验的75个参试品种的面粉糊化特性。结果表明,我省小麦品种糊化性状变异范围较大;面粉的糊化特性在不同的种植区域表现不同,粘度参数有随地区纬度增高而增加的趋势;环境变异越大,小麦淀粉特性差异越大。     

大米糊化特性曲线探讨

本文利用Brabebder淀粉粘度仪,详细研究了糯型与非糯型大米样品在特殊情况下其糊化特性有明显的差别.在糊化特性曲线上发现糯米型最高粘滞峰值低于非糯型,它与这两种类型大米的α——淀粉酶含量成负相关,与直链淀粉含量和糊化温度成正相关.     

不同介质对糯米淀粉糊化特性的影响

采用Brabender黏度仪,测定糯米淀粉糊在不同浓度的碱面、明矾、食盐和蔗糖条件下的黏度曲线,研究了这些因素对糯米淀粉糊化特性的影响.结果表明,添加碱面、明矾、食盐和蔗糖提高了糯米淀粉的糊化温度、热稳定性,减弱了老化程度.碱面、明矾、食盐对糯米淀粉糊化特性影响较大,而蔗糖的影响较小.     

小麦籽粒A、B型淀粉粒淀粉构成与糊化特性的比较

以提纯的小麦胚乳A型和B型淀粉粒为测定对象,比较研究了A、B型淀粉粒的淀粉组成与糊化特性.结果表明,A型淀粉粒直链淀粉含量显著高于B型淀粉粒,而支链淀粉含量显著低于B型淀粉粒.与B型淀粉粒相比,A型淀粉粒含有较高的直/支链淀粉比.B型淀粉粒RVA参数中峰值粘度、低谷粘度、稀懈值、最终粘度、反弹值、峰值时间和糊化温度均显...     

春季灌水次数对强筋小麦淀粉组分与理化特性的影响

为探究春季灌水次数对冀东平原强筋小麦籽粒淀粉含量及其理化特性的影响,选用中麦998和津农7号2个强筋小麦品种,分析了3个灌水次数(W0春季不灌水;W1拔节水;W2拔节水+开花水)对强筋小麦籽粒淀粉含量及其组分含量、热力学特性、糊化特性和晶体特性的影响,并对淀粉组分与淀粉理化特性进行了相关性分析.结果表明:春灌拔节水(W1)显著提高了2品种的支链淀粉和总淀粉含量,中麦998提高了9.88％,8.45％,津农7号提高了9.35％,6.34％;且春灌拔节水(W1)时产量较高,仅次于W2处理.随灌水次数增加,2个品种的高峰温度、糊化焓先上升后下降;但峰值粘度和稀懈值以W0处理最高,糊化时间先上升后下降,最终粘度和糊化温度存在品种间差异,中麦998先上升后下降,而津农7号呈上升趋势;晶体强度和相对结晶度先上升后下降.相关分析表明,直链淀粉含量与谷值粘度呈显著正相关;支链淀粉含量与高峰温度、终止温度、糊化焓、糊化温度、糊化时间、相对结晶度呈显著或极显著正相关,与峰值粘度、稀懈值呈极显著负相关.综上所述,本试验条件下,春灌拔节水可以有效提高强筋小麦支链淀粉含量、总淀粉含量及籽粒产量,进而影响淀粉理化特性;与直链淀粉相比,支链淀粉含量与淀粉理化特性更密切相关.     

脂类在稻米陈化过程中的变化及与稻米糊化特性的关系

糙米分别在38℃和8℃条件下储藏6个月,非淀粉脂脂肪酸变化较大,其中软脂酸和亚油酸相对减少,油酸相对含量增加。而淀粉脂脂肪酸变化很小。淀粉脂和非淀粉肥中的糖脂和磷脂含量下降,杨脂下降速度较快,磷脂下降速度较慢。用粘度仪和差分扫描量热仪对不同条件下储藏的糙米粉、脱脂糙米粉进行分析,结果表明,脱去非淀粉脂的样品与对照相比,糊化特性值降低,说明脂类对稻米的糊化特性确有影响。脱去非淀粉脂能改善糙米储藏稳定性。     

籽粒品质和淀粉组分对面粉糊化特性的影响

为了解析面粉糊化特性与籽粒品质和淀粉组分的相关关系,以70份农家种及高代为研究对象,分析糊化参数与籽粒品质(籽粒蛋白质含量、籽粒硬度、千粒质量和容重)和淀粉组分含量的相关关系。结果显示,除了与籽粒蛋白质含量和支链淀粉含量,面粉糊化参数与籽粒品质和淀粉组分的其他性状、指标均存在不同程度的相关性:直链淀粉含量与稀澥值和反弹值相关度较高(r=-0.67和0.62),而与峰值粘度和最终粘度相关度较低(r=-0.48和0.45);籽粒硬度与糊化温度高度负相关(r=-0.84),与峰值粘度、反弹值和糊化时间也显著相关,但相关系数较低,分别为-0.28,0.33和0.36;千粒质量与稀澥值和糊化温度低度相关(r=-0.27和-0.26),而容重与低谷粘度和最终粘度相关度较高,相关系数分别为0.43和0.40。总之,稀澥值和反弹值主要与直链淀粉含量相关,高稀澥值和低反弹值在较大程度上表明直链淀粉含量偏低,并且,高峰值粘度和低最终粘度往往也表明直链淀粉含量偏低;容重偏高往往意味低谷粘度和最终粘度也较高;籽粒硬度偏高在很大程度上预示糊化温度偏低。     

Mixolab参数与粉质、拉伸参数及面包烘烤品质的关系

根据仪器测定的面粉品质特性预测面包烘烤品质是进行小麦品质改良的重要方法。法国肖邦公司(Chopin Technologies, France)最新推出的Mixolab分析仪可以同时测定面粉加水后恒温揉混及面团升温后蛋白质弱化和淀粉糊化特性,明确其与现有相似仪器如粉质仪和拉伸仪等的关系对小麦品质测试具有重要意义。利用 Mixolab分析仪、粉质仪、拉伸仪测定了41份高代育种品系的有关参数和面包烘烤品质,并分析了Mixolab与粉质仪和拉伸仪相关参数的关系及预测面包品质的可靠性。结果表明,可以用Mixolab的形成时间、稳定时间、面团受热后蛋白质弱化值(C2值)和到达淀粉糊化反弹值的时间(C4时间)来预测粉质仪和拉伸仪的品质参数,可解释其变异的74%~90%;可以直接用C2值预测面包体积、外观、结构和总分,决定系数分别为52%、73%、70%和68%;预测面包质地和弹性的参数不仅包含Mixolab稳定时间和C2值,还有表示淀粉糊化特性的C3时间、C4和C5值及C5温度。用Mixolab分析仪既可以了解蛋白质特性和面包烘烤品质的关系,又明确了淀粉品质对面包品质的显著影响,在品质测试中有其独特之处。Mixolab、粉质仪和拉伸仪各参数对预测小麦面包体积、内部质地结构等烘烤品质性状的贡献不同。     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Relation between wheat-rye crossability and seed set of common wheat after pollination with other species in the Hordeae

Summary Cultivars of common wheat (Triticum aestivum L. em. Thell.) of high wheat-rye (Secale cereale L.) crossability set more seed with pollen of other related species than did wheats of low wheat-rye crossability. This was found to be true for pollen parents from the genera Triticum, Aegilops, Secale, Agropyron and Elymus.     

Breeding apomictic bahiagrass (Paspalum notatum Flügge) with improved turf traits

The development of a turf‐type bahiagrass could have a remarkable impact on the billion‐dollar turf industry in the south‐eastern United States. The goals of this study were to (i) select bahiagrass genotypes with improved turf attributes and (ii) determine the reproductive mode and seed fertility of selected genotypes. The population included mutants, wild types, hybrids and standard cultivars evaluated at two locations for two years. Morphological variation was observed and clonal repeatability (H²) ranged from 0.27 to 0.90. Flowering was extremely reduced in some mutants, which also exhibited dark green colour, finer texture and reduced canopy height. Cytoembryological observations revealed that diploids reproduced sexually and tetraploids by obligate or facultative apomixis. Genotypes with superior seed fertility were identified, while others were comparable to the standard cultivars. While mutant plants exhibited great morphological variation, the random mutations did not affect their reproductive mode, validating the use of mutagenesis in apomictic species. The high H² indicated that selection for improved turf attributes could be successfully performed with the advantage of clonal seed propagation.     

Inheritance of fruit colour in a wild Russian red raspberry seedling

Summary A new gene, i, from a self-incompatible wild Russian Rubus idaeus seedling is described. The gene i interacts with the fruit colour gene T, Tii plants having apricot instead of red fruits, and spines, leaves and stems pigmented to varying degrees. A deficit of apricot-fruited seedlings in progenies segregating for i could be explained by linkage between i and the self-incompatibility S locus with a crossover value of approximately 26.7%.Segregations for spine colour in crosses and backcrosses of the Russian seedling with two green-spined (ttII) raspberries selected for their yellow fruit colour, showed that both the latter carried the spine colour intensifier gene P. This suggests that earlier authors were incorrect in attributing the apricot fruit colour developed by some tt plants to a pleiotropic effect of P.     

Flag Leaf Senescence, as Evaluated by Numerical Image Analysis, and its Relationship with Yield under Drought in Durum Wheat

Senescence was evaluated at different stages of the grain‐filling period in eight durum wheat varieties using numerical image analysis (NIA). The varieties were grown under early, severe drought conditions on the high plains of Sétif in Algeria. After flowering, three different irrigation treatments were applied. Treatment effect was small, while a genotypic effect was noted for most of the senescence parameters. Senescence correlated to biomass, while the maximal rate of senescence, V_smax, correlated to thousand‐kernel weight. The potential of the method of numerical image analysis for monitoring flag leaf senescence, detecting genotypic variability and selecting genotypes with delayed senescence is discussed.     

Mechanisms and diversity of resistance to sorghum shoot fly,Atherigona soccata

Sorghum shoot fly, Atherigona soccata, is one of the important pests of postrainy season sorghums. Of the 90 sorghum genotypes evaluated for resistance to this pest, RHRB 12, ICSV 713, 25026, 93046 and 25027, IS 33844‐5, Giddi Maldandi and RVRT 3 exhibited resistance in postrainy season, while ICSB 463, Phule Anuradha, RHRB 19, Parbhani Moti, ICSV 705, PS 35805, IS 5480, 5622, 17726, 18368 and 34722, RVRT 1, ICSR 93031 and Dagidi Solapur showed resistance in rainy season, suggesting season‐specific expression of resistance to A. soccata. ICSB 461, ICSB 463, Phule Yasodha, M 35‐1, ICSV 700, 711, 25010, 25019 and 93089, IS 18662, Phule Vasudha, IS 18551 and 33844‐5 and Barsizoot had fewer deadhearts than plants with eggs across seasons, suggesting antibiosis as one of the resistance mechanism. Five genotypes exhibited resistance with high grain yield across seasons. Correlation, path and stepwise regression analyses indicated that leaf glossiness, seedling vigour, trichome density, oviposition and leaf sheath pigmentation were associated with the expression of resistance/susceptibility to shoot fly, and these can be used as marker traits to select and develop shoot fly‐resistant sorghums.     

Cowpea (Vigna unguiculata): Genetics,genomics and breeding

Cowpea, Vigna unguiculata (L.), is an important grain legume grown in the tropics where it constitutes a valuable source of protein in the diets of millions of people. Some abiotic and biotic stresses adversely affect its productivity. A review of the genetics, genomics and breeding of cowpea is presented in this article. Cowpea breeding programmes have studied intensively qualitative and quantitative genetics of the crop to better enhance its improvement. A number of initiatives including Tropical Legumes projects have contributed to the development of cowpea genomic resources. Recent progress in the development of consensus genetic map containing 37,372 SNPs mapped to 3,280 bins will strengthen cowpea trait discovery pipeline. Several informative markers associated with quantitative trait loci (QTL) related to desirable attributes of cowpea were generated. Cowpea genetic improvement activities aim at the development of drought tolerant, phosphorus use efficient, bacterial blight and virus resistant lines through exploiting available genetic resources as well as deployment of modern breeding tools that will enhance genetic gain when grown by sub‐Saharan Africa farmers.     

Screening for resistance to take-all in wheat,triticale and wheat-triticale hybrid lines

Summary Fifteen triticale and wheat-triticale hybrid lines were evaluated for resistance to the take-all fungus Gaeumannomyces graminis var. tritici and compared with five wheat and two rye lines in inoculated field and pot trials. The triticale and wheat-triticale hybrid lines varied in rye chromosome number and degree of resistance expressed. One line, Venus with seven pairs of rye chromosomes consistently showed levels of resistance intermediate between wheat and rye. A trend was observed where increasing rye chromosome content led to greater resistance but exceptions showed that variation within triticales could not be ascribed to rye chromosome content alone.     

Reaction of tritordeum to Fusarium culmorum and Septoria nodorum

Summary Hordeum chilense is a wild barley extensively used in wide crosses in the Triticeae. It could be a valuable source of resistance to Fusarium culmorum and Septoria nodorum. Some H. chilense x Triticum spp. amphiploids, named tritordeums, were more resistant than the parental wheat line to these diseases, others were not. Average contents of ergosterol and deoxynivalenol (DON) suggested that resistance to colonization by Fusarium was the highest for Hordeum chilense, followed by tritordeum and wheat in decreasing order. In particular, the H. chilense genotypes H7 and H17 enhanced the wheat resistance to F. culmorum in its tritordeum offsprings. Resistance to S. nodorum in tritordeum was not associated with tall plant height. There is sufficient genetic variation for resistance to F. culmorum and S. nodorum among tritordeum to allow the breeding of lines combining short straw and resistance to both diseases.