Quality Improvement of Upland Cotton (Gossypium hirsutum L.)

Abstract

Quality of cotton can be defined through seed or fiber properties, but is most often associated with fiber properties that influence processing into yarn and textile products. Global competition in the production and consumption of cotton fiber combined with technological evolution of yarn manufacturing has spurred renewed efforts to enhance cotton fiber quality. Cotton fiber quality can be improved through genetics, crop management, and postharvest processing. Knowledge of the effects of fiber properties on processing and their inheritance, relationships, and environmental influences is necessary to formulate improvement strategies. Breeding to improve fiber quality has traditionally focused on enhancing measures of the longest fibers or fiber strength for ring yarn manufacturing systems. With the technological evolution of yarn manufacturing from solely ring-based spinning to predominately rotor and potentially in the near future air-jet spinning, needs for fiber profiles have been revised for these spinning systems. Successful rotor spinning requires high fiber strength for all yarn counts, along with fiber fineness for fine count yarns. The even more productive air-jet spinning requires a minimum, but uniform fiber length, fiber fineness, and to a lesser extent strong fiber. In contrast, ring spinning requires a minimum fiber length, fiber strength, and to a lesser extent fiber fineness. Breeders do not conduct direct selection for yarn properties because of impracti-calities, thus they select for fiber properties that influence processing, so-called indirect selection. The inherent environmentally induced variability in fiber properties presents challenges to enhance them through breeding or biotechnological approaches. Because variability in fiber properties is problematic to fiber processing, future-breeding and biotechnological approaches should simultaneously focus on enhancing fiber properties and reducing variation. This paper will review strategies to enhance fiber profiles through genetic approaches while ameliorating their variation.     

Dependence of Grain Weight of Spring Barley Genotypes on Traits of Individual Stems

Abstract

The aim of the paper is to evaluate relationships between some plant traits and grain weight per spike of spring barley (Hordeum vulagre L.). Field trials were conducted in 1999, 2001, and 2002 in central Poland. Data were collected on morphological traits of individual plants of two cultivars, Rasbet and Rastik. The data were analyzed using path analysis. Causal relationships studied were similar for both cultivars: grain weight per spike was determined mainly by number of grains per spike (path coefficient was 0.723 for Rasbet and 0.700 for Rastik), whereas the effect of mean kernel weight was weaker (0.487 for Rasbet and 0.510 for Rastik). The only noticeable indirect effect was that of spike length on grain weight per spike via number of grains per spike (0.490 for Rasbet and 0.468 for Rastik); all the indirect effects of shoot length on grain weight per spike were negligible. We concluded that to develop new semi-dwarf and dwarf genotypes, emphasis should be placed on increased number of grains, kernel weight, and spike length.     

Pressure evaluation of 3D seamless knitted bras and conventional wired bras

Seamless knitting for making bras is a novel approach. The fitting evaluation of these products remains unknown and there is limited knowledge about the effects of knitting parameters on the bra tension. This study developed 3 styles of seamless knitted bras with various loop length and elastic yarn tension based on a 2² full factorial experimental design with one additional centre level. Therefore, a total of 3 × 5= 15 new seamless bra samples have been knitted. The skin pressure exerted by the new bras was compared with 4 commercial bras including 2 “cut and sewn” wired bras and 2 seamless knitted bras. Six women subjects of breast size 75B* in our newly developed breast sizing system were invited to wear all the bra samples. The skin pressure exerted by the bra was measured by the Novel pliance-X pressure sensors on 11 body positions. The results indicated that newly developed seamless bras showed lower pressure than the commercial bras, but had a considerably higher pressure at the cup base point. The new seamless bras with the largest loop length presented the lowest pressure values. Furthermore, empirical equations were established to predict 2 critical pressure points at “apex” and “side bottom band” from two major knitting parameters. This study provides the new knowledge of seamless knitted bra fitting and the resulted bra pressure, as well as some guidelines for seamless knitted product design and manufacturing.     

长期不同施肥模式下砂姜黑土小麦根系和光合的差异性研究

为明确长期单一施肥模式效果间的差异,研究了5种长期定位(34年)施肥模式对砂姜黑土小麦根系和光合的影响。结果表明,CK(不施肥)的根系性状表现最差,MNPK(有机肥与化肥配施等氮)与HMNPK(有机肥与化肥配施高氮)的总根长、总根表面积、总根体积和总根尖数显著高于NPK(单施化肥)和M(单施有机肥)处理,NPK与M间的总根表面积、平均根直径、总根体积差异不显著。长期有机肥与化肥配施(MNPK和HMNPK)相对于长期单施化肥(NPK)和有机肥(M)能提高小麦上3叶的长宽。在孕穗期,MNPK的光合速率、气孔导度和蒸腾速率最高,但与HMNPK差异不显著;在灌浆中期(MNPK与HMNPK发生倒伏),NPK和M处理的光合特性表现优于有机肥与化肥配施处理MNPK和HMNPK,MNPK的光合特性亦优于HMNPK(倒伏最重)。在孕穗期,有机肥与化肥配施相对于长期单施化肥和有机肥利于小麦叶绿素荧光参数的改善;灌浆中期,M处理的叶绿素荧光参数表现最优,MNPK的ΦpsⅡ、Fv/Fm、ETR、qP显著高于HMNPK。总根长、总根表面积、平均根直径、总根体积、总根尖数皆与光合高效叶片长宽及产量呈显著或极显著正相关关系;根系性状、产量与光合特性、叶绿素荧光参数Fm、ΦpsⅡ、Fv/Fm、ETR、qP呈显著或极显著正相关关系,与胞间CO_2浓度、Fo、qN呈极显著负相关关系。研究得出,有机肥与化肥配施虽有利于小麦根系及高效光合叶片长宽的改善,但有机肥与化肥配施高氮下遇特殊天气由于肥力较高易发生倒伏,造成光合速度的下降。     

全长cDNA文库的构建方法

全长cDNA文库的构建是进行功能基因组研究的一种经济、快速、有效的途径,克服了传统cDNA文库的缺点,节省了基因克隆和功能鉴定的时间,促进了功能基因组的研究进程。目前有6种构建全长cDNA文库的方法,包括Oligo-Capping、CAPture、SMART、CAP-trapper、CapSelect、CAP-jumping。这几种方法在起始材料用量、文库构建技术、实验操作复杂程度和文库构建质量等方面构存在不同程度的优缺点,但综合比较而言,SMART和CAP-trapper这两种方法比较有实际应用价值。SMART法适于简单、快速地构建一般质量的cDNA文库,如果采用Little-cycle SMART和Large-size SMART这两种改进技术,所建文库质量也非常好;CAP-trapper法虽然对实验技术要求较高,实验过程复杂,但所建文库全长率高,冗余性低,建库效率高,是目前构建高质量文库最好的方法。     

优良水稻染色体片段代换系Z746的鉴定及重要农艺性状QTL定位及其验证

粒型、株高及穗部组成性状与产量形成密切相关,是水稻重要农艺性状,但遗传基础复杂。染色体片段代换系是用于复杂性状遗传研究的良好材料。本研究鉴定了一个以日本晴为受体、西恢18为供体亲本的水稻优良染色体片段代换系Z746。Z746携带来自西恢18的7个代换片段,平均代换长度为3.99 Mb,其株高、粒长和穗部性状均与受体存在显著差异。进一步通过日本晴与Z746杂交构建的次级F2群体共检测到36个相关QTL,分布于2号、3号、4号、6号和11号染色体。其中5个可能与已克隆基因等位,如qPH3-1等, 8个可被多次检出,表明这些是遗传稳定的主效QTL。Z746的粒长主要由4个QTL(qGL3、qGL4、qGL2、qGL6)控制,其中qGL3和qGL4对粒长变异的贡献率分别为60.28%和27.47%。株高由5个QTL控制,穗长由4个QTL控制,每穗粒数由2个QTL控制,千粒重由2个QTL控制。然后以MAS在F3共选出8个单片段代换系,并以此在F4进行了相关QTL验证,共有24个QTL可被8个单片段代换系(SSSL)检出,重复检出率为66.7%,表明这些QTL遗传稳定。本研究为目的 QTL的进一步...     

氮响应转录因子Zm NLP5影响玉米根系生长的功能研究

研究作物氮高效机制并挖掘利用其中重要的调控基因,对我国农业绿色发展具有重要意义。前期我们发现氮响应转录因子ZmNLP5调控亚硝酸还原酶基因的表达,对玉米氮素吸收利用具有促进作用,但其调控机制尚未明确。基于此,本研究以ZmNLP5基因突变体(zmnlp5)和野生型(WT)植株为研究材料,深入解析ZmNLP5影响玉米氮素吸收利用的生理机制。足氮(sufficient nitrogen, SN)和低氮(deficient nitrogen, DN)条件下研究材料表型分析发现, DN条件下相对于WT植株, zmnlp5植株根长显著降低。根部不同区域ZmNLP5表达量分析发现, ZmNLP5主要在根尖区域表达。不同亚硝酸盐浓度处理下,研究材料的根长和根尖区域亚硝酸盐含量分析发现,当亚硝酸盐的浓度高于2mmol L~(-1)时,zmnlp5突变体根长相对于WT显著降低,zmnlp5植株根尖区域亚硝酸盐积累量显著高于WT。SN和DN条件下研究材料根部亚硝酸盐含量检测发现, DN条件zmnlp5植株根尖区域所积累的亚硝酸盐也显著高于WT。综上所述,转录因子ZmNLP5在玉米植株响应低氮环境根部伸长生长中发挥重要功能,该结果为玉米氮高效育种提供了一定的理论基础。     

Quantitative trait loci (QTL) mapping of silique length and petal colour in Brassica rapa

Recombinant inbred lines (RILs) derived from a cross between Brassica rapa L. cv. ‘Sampad’, and an inbred line 3‐0026.027 was used to map the loci controlling silique length and petal colour. The RILs were evaluated under four environments. Variation for silique length in the RILs ranged from normal, such as ‘Sampad’, to short silique, such as 3‐0026.027. Three QTL, SLA3, SLA5 and SLA7, were detected on the linkage groups A3, A5 and A7, respectively. These QTL explained 36.0 to 42.3% total phenotypic variance in the individual environments and collectively 32.5% phenotypic variance. No additive × additive epistatic interaction was detected between the three QTL. Moreover, no QTL × environment interaction was detected in any of the four environments. The number of loci for silique length detected based on QTL mapping agrees well with the results from segregation analysis of the RILs. In case of petal colour, a single locus governing this trait was detected on the linkage group A2.     

甘蓝型油菜角果长度的主+多基因混合遗传模型

角果是油菜产量构成要素中重要的组成部分。本文以长角果品种中双11和短角果材料10D130为亲本配制杂交组合,采用主基因+多基因混合遗传模型分析方法对该组合6世代遗传群体(P₁、P₂、F₁、BCP₁、BCP₂和F₂)的果身长、角果长和果喙长进行遗传分析。结果表明,该组合的3个角果性状均呈连续分布,其中,果身长最适遗传模型为E-0 (2对加性-显性-上位性主基因+加性-显性-上位性多基因模型),2对主基因加性效应值分别是1.75和–0.06,显性效应值分别是–0.59和–0.86,主基因遗传率在BCP₁、BCP₂和F₂中分别是51.10%、74.23%和66.93%,多基因遗传率分别为29.16%、17.11%和23.96%。角果长的最适遗传模型为E-1 (2对加性-显性-上位性主基因+加性-显性多基因模型),其中,第1对主基因加性效应为0.34,显性效应为–0.81,第2对主基因加性效应为0.34,显性效应为–0.47,主基因遗传率在BCP₁、BCP₂和F₂中分别是47.63%、68.51%和79.45%,多基因遗传率分别为29.40%、20.89%和12.47%。果喙长的最适遗传模型为E-3模型(2对加性主基因+加-显多基因遗传模型),2对主基因加性效应值分别是0.2和–0.2,主基因遗传率在BCP₁、BCP₂和F₂中分别是33.71%、72.75%和52.25%,多基因遗传率分别为40.08%、5.37%和27.60%。