Commentary on two misconceptions of phylogeny and classification

A recent brief communication criticizes a morphometric study of the structure of Daubentonia (Oxnard, 1981). The criticisms are invalid because they apply to the concept of the detailed character state in a localized anatomical region, a type of morphological information different than the broad measurement that embodies many characters. The criticisms themselves display, moreover, exactly those problems of prior assumption that the underlying philosophy of multivariate morphometric studies as used by Oxnard (1981) tries to eliminate.     

Recovery of plains rough fescue grasslands on reclaimed well sites

Plains rough fescue (Festuca hallii), once dominant in grasslands of the Northern Great Plains, has been reduced to remnants mainly through agricultural and energy sector development. This study assessed the impacts of oil and gas well site disturbances on plains rough fescue grassland to predict successional trends following disturbance. We examined trends in vegetation cover, richness, diversity, and community composition for two construction techniques (topsoil stripping, minimum disturbance), three revegetation methods (agronomic seed mix, native seed mix, natural recovery), and two reclamation scenarios (reclaimed within < 10 yrs; reclaimed within > 10 yrs) relative to adjacent undisturbed prairie (reference sites) over 28 years in 33 grassland sites. Reclamation success was more closely related to methods of construction and revegetation than years since reclamation. Species richness, diversity, both native and non-native species cover, and species composition were similar between undisturbed prairie and areas subject to minimum disturbance and natural recovery. In contrast, undisturbed prairie differed from areas with topsoil stripping and seeding to either agronomic or native species. Plant community composition on minimum disturbance sites with natural recovery was returning to a predisturbed plains rough fescue community within 10 years after reclamation. Impacts of construction method that involved intensive soil handling and seeding with native or non-native seed mixes were disruptive to recovery of fescue grassland. We therefore recommend retaining grassland sod intact through minimum disturbance and utilizing natural recovery as the best option for successful reclamation of native rough fescue grassland after well site disturbance.     

Hd1, Ghd7, and DTH8 synergistically determine the rice heading date and yield-related agronomic traits

Heading date determines the seasonal and regional adaptation of rice (Oryza sativa L.) varieties and is mainly controlled by photoperiod sensitivity (PS). The core heading date genes Hd1, Ghd7, DTH8, and PRR37 act synergistically in regulating the PS. In this study, we systematically analyze the heading date, PS, and agronomic traits of eight homozygous lines with various combinations of Hd1, Ghd7, and DTH8 alleles in the prr37 background under long-day (LD) and short-day (SD) conditions, respectively. We find that Hd1 alone promotes heading, regardless of the day length. However, under LDs, Hd1 suppresses flowering, in coordination with functional Ghd7 or with Ghd7 and DTH8. These loci cooperate to negatively regulate the Ehd1-Hd3a/RFT1 pathway and delay heading. Under SDs, Hd1 competes with various heading suppressors to promote heading. Therefore, the dual function of Hd1 is vital for PS. The lines carrying Hd1 alone show reduced plant height with fewer primary and secondary branches in panicles. Lines carrying Ghd7 and DTH8 (with hd1) show delayed heading and improve agronomic traits. Overall, our results reveal the regulation of rice PS flowering by the core heading date genes and their effects on agronomic traits, providing valuable information for the selection of rice varieties for adaptation to different light and temperature conditions.     

水稻不同基因型耐低氮能力差异评价

以水稻单株谷重及其氮素反应指数作为耐低氮能力指标,分析不同施氮水平下水稻种质资源的耐低氮能力以及单株谷重及其氮素反应指数与其他农艺性状的相关关系。结果表明,水稻种质资源的耐低氮能力在不同施氮水平间均有较大差异,多数农艺性状的表型差异顺序为未施氮〉施低氮〉普通施氮;不同施氮水平间单株谷重、单株草重和穗数的差异大于其他农艺性状。在不同施氮水平下,单株谷重与单株草重均呈极显著正相关;单株谷重的氮素反应指数与单株谷重、单株草重和谷草比均呈极显著正相关。在未施氮水平下,单株谷重与株高、穗数、穗粒数和单株草重的相关性以及单株谷重的氮素反应指数与穗数、单株谷重、单株草重和谷草比的相关性比施低氮或普通施氮水平更为密切。花峰稻、中作9059、旱稻9号、旱稻502和IRAT359等种质资源表现较迟钝的氮素反应,具有较强的耐低氮能力。     

转基因抗虫棉农艺性状和纤维品质的遗传多样性

本研究以国内育成和国外引进的52份转基因抗虫棉品种(系)为材料,在河北农业大学棉花育种圃种植,调查农艺性状、测定纤维品质,基于农艺性状和纤维品质分析供试品种(系)的遗传多样性.结果表明:在9个农艺性状中,烂铃数的变异系数最大,其次为产量、有效铃数和第一果枝节位高度,变异系数最小的是衣分和果枝数.转基因抗虫棉品种纤维长度基本能够满足纺织工业需求,2.5%跨长主要集中在28～30mm;纤维比强度平均值为27.1cN/tex,变幅为23.0～31.6cN/tex;马克隆值的平均值为4.8,变幅为4.0～5.6.成对品种的欧氏距离变化在1.53～13.31之间,平均值为4.79,单一品种欧氏距离的平均值分布在3.62～10.51之间,表明不同品种之间具有一定的差异.采用离差平方和法对欧氏距离进行聚类,可以将供试品种明显地划分为2类,一类为中熟品种,另一类为早熟品种.     

利用农艺性状和SRAP标记方法初步鉴定甘薯丰收白突变体

采用UPGMA法对11个甘薯品种（系）不同农艺性状进行聚类分析。在相似系数为0.17处被划分为三大类群,分别包括2、3、6个品种。SRAP聚类分析表明：在相似系数为0.77处,第Ⅱ类群划分为2个亚簇：ⅡA和ⅡB,ⅡA有3个品种,ⅡB有3个品种;在相似系数为0.75处,第Ⅲ类群划分为2个亚簇：ⅢA和ⅢB。ⅢA有2个品种,ⅢB有2个品种。丰收白野生型与突变体M-0在农艺性状以及SRAP分子标记的聚类分析中均聚为一类。对丰收白野生型及其突变体M-0的叶型、叶脉颜色、新生叶色、薯皮色、薯形及肉色6个生物学性状进行观察比较,结果表明二者在前5个性状均未表现出明显差别,只在薯色性状上表现明显差异即丰收白的薯肉色为白色而突变体M-0为粉红色。突变体丰收白M-0和丰收白野生型多态性条带比率为29.49%,有效等位基因数为1.2085,说明二者在遗传上差异不明显,并且初步推断丰收白M-0是丰收白的薯肉色基因发生点突变的结果。     

Über die weite Verbreitung lichenisierter Sippen vonDictyochloropsis und die systematische Stellung vonMyrmecia reticulata (Chlorophyta)

Catinaria grossa is lichenized withDictyochloropsis splendida var.gelatinosa, var. nova. When cultured isolated from the fungus the cells of this variety are covered individually by thick gelatinous envelopes. The phycobionts ofMegalospora gompholoma subsp.gompholoma andM. atrorubicans subsp.australis belong to a new variety ofD. symbiontica, i.e. var.pauciautosporica, which preferentially reproduces by zoo- and aplanospores. The phycobiont ofPseudocyphellaria aurata does not belong toMyrmecia reticulata as formerly thought, but toDictyochloropsis symbiontica. Specimens from one locality in Tenerife and from New Zealand are lichenized with a strain ofD. symbiontica var.symbiontica, those from another locality in Tenerife with a strain ofD. symbiontica var.pauciautosporica. These strains differ in certain characters from other lichenized strains of these varieties.

     

Effect of Plant Growth Regulators on Agronomic Characteristics,Lint Quality,Pests, and Predators in Cotton

Field experiments were conducted with some commercial plant growth regulators (PGRs) to determine their effects on agronomic characteristics, pest densities, and predators when administered as a foliar spay on cotton at Adnan Menderes University Agricultural Research Center located in Aydin, Turkey, during the 2006 and 2007 cotton-growing seasons. The three commercial PGRs, Pix, Tonic, and Turbo pamuk, were sprayed at recommended doses and application time during the study. Application of PGRs significantly positively affected the yield, plant height, average number of open bolls, and predators, and significantly decreased the population densities of some economically important cotton pests. However, lint quality, ginning turnout, and average of seed cotton weight were not affected by the treatments. More yield was obtained in Pix- and Turbo pamuk-treated plots. The lowest densities of Bemisia tabaci, Frankliniella spp., and leaves infested with Liriomyza trifolii were recorded in Pix-treated plots. Although Turbo pamuk and Tonic numerically lowered the pest population densities compared to the control, the changes were not significant and these PGRs were not as effective as Pix. Furthermore, Empoasca spp. was not affected by the treatments. Populations of predators were not affected by the PGRs in Aranea orders, but were affected in Heteroptera, Neuroptera, Coleoptera, and Thysanoptera. Pix proved more suitable than others to producing resistance against pests and increasing the yields. PGRs neither enhanced any insect attack nor reduced predators in the study. Therefore, PGRs may be considered a component of Integrated Pest Management to provide higher yields in cotton.     

谷子主要育成品种在新疆的遗传多样性研究

以274份谷子种质资源为材料,利用聚类分析和主成分分析方法,对参试资源16个农艺性状的遗传多样性进行综合评价。结果表明,参试材料的11个数量性状的遗传多样性指数均大于2.000,在新疆表现出广泛的遗传多样性。基于种质资源间形态标记的遗传差异,将274份谷子种质资源聚类并划分为6大类群。第Ⅰ类群(105份材料)生育期较短,属早熟类型,但其他性状表现一般;第Ⅱ类群(19份材料)出苗-抽穗日数最小,全生育期最短,早熟性明显,穗下节间长度相对其他类群较长;第Ⅲ类群(10份材料)生育期较短,主穗长相对较长,其余性状表现均处于较低水平;第Ⅳ类群(58份材料)主穗长、单穗重在各类群中处于较高水平,生育期相对较短;第Ⅴ类群(26份材料)生育期最长,属晚熟类型,除主穗长度最小外其余性状均表现突出;第Ⅵ类群(56份材料)生育期相对较长,属中晚熟类型,株高较低,生物产量处于中等水平。9个数量性状的主成分分析结果表明,前3个主成分因子(单株秆重、株高、主穗直径)累计贡献率达70.41%,各主成分因子性状载荷值反映了育种中各性状的选择方向及潜力。综合评价谷子种质资源农艺性状,为新疆谷子资源收集、评价和利用提供一定的科学依据。     

应用变色法筛选斑玉蕈优良杂交子

【目的】将变色检测方法应用于斑玉蕈优良杂交菌株的选育,缩短育种过程。【方法】采用分光光度计检测变色培养基的颜色变化,计算脱色率(D值)。【结果】变色检测培养基的颜色变化和脱色率(D值)是一致的,即培养基显示黄色时D值是正值,培养基显示蓝色时D值是负值。D值与斑玉蕈主要农艺性状具有紧密联系,D值是正值的菌株平均吃料速度比D值是负值的菌株快,单瓶产量和正常子实体数与D值呈正相关性,畸形菇数与D值呈负相关性。【结论】应用变色检测法可以快速简单地筛选出优良菌株,缩短斑玉蕈育种进程。