不同栽培环境条件对优质杂交稻培杂双七稻米品质的影响研究

通过在不同地区、不同季节进行不同插植密度和施肥条件的大田种植试验,对培杂双七稻米品质的变化进行了研究.结果表明:华南稻区早晚季种植、珠江三角洲地区和丘陵地区种植以及不同插植密度和混施硅肥、沸石均对部分品质性状产生显著的影响,但是所有这些环境条件中没有一种能明显改善该组合的全部品质性状或稻米的综合品质.因此,杂交稻的综合品质改良,只有通过不育系和恢复系的遗传改良才能从根本上解决问题.     

美国大豆品种改良过程中生理特性变化的研究进展

育种者通过遗传改良大幅度提高了大豆的产量，同时生理特性也发生较大的变化，鼓粒期(seed filling period，SFP)干物质积累、N积累、光合效率及叶面积持续期明显增加；子粒蛋白质相对含量呈下降趋势，而油份含量有所增加；耐密、抗倒伏特性增强，但抗旱特性有所减弱。在中国不同区域内开展大豆基因改良过程中生理变化的研究将对未来新品种的研发产生重要影响。各种专用化的大豆品种的培育将是大豆育种的发展方向。     

大豆品种产量与有关性状的相关和通径分析

与大豆产量相关的各生育性状中,生育期、株高、分枝、主茎节数、单株荚数、百粒重等都与产量性状呈正相关,其中相关分析表明,分枝、单株荚数与产量的正相关系数分别为0.545,0.488,达到了显著水平,生育性状与产量的通径分析表明,分枝数、单株荚数对产量的直接效应较大,与相关分析的结果一致.     

相同遗传背景下7 8与17 18亚基对小麦理化品质的影响

为准确研究不同高分子量麦谷蛋白亚基（HMW-GS）对小麦品质的贡献，消除因取材不同对结果的影响，用甘春20号（1，7＋8，5＋10）和永良4号（1，17＋18，5＋10）分别进行正、反交，使其杂种后代间具有相同的遗传背景，在杂种F3代选择只有7＋8亚基和17＋18亚基差异的单株，对两种类型籽粒的理化品质进行了分析。结果表明，对于蛋白质含量、灰分含量、沉淀值、面筋含量和降落数值，7＋8亚基和17＋18亚基的贡献无明显差别，亚基效应为7＋8=17＋18；对于颗粒度和面筋指数，7＋8亚基的贡献明显大于17＋18亚基，差异达到极显著水平，亚基效应为7＋8〉17＋18；对于出粉率，17＋18亚基的贡献明显大于7＋8亚基，亚基效应为7＋8〈17＋18，差异也达到极显著水平。     

Model predicting dynamics of biomass, structure and digestibility of herbage in managed permanent pastures. 1. Model description

To investigate seasonal and annual interactions between management and grassland dynamics, a simple mechanistic model of the dynamics of production, structure and digestibility in permanent pastures was constructed. The model is designed to respond to various defoliation regimes, perform multiple‐year simulations and produce simple outputs that are easy to use as inputs for a model of ruminant livestock production. Grassland communities are described using a set of average functional traits of their constituent grass groups. The sward is subdivided into four structural compartments: green leaves and sheath, dead leaves and sheath, green stems and flowers, and dead stems and flowers. Each compartment is characterized by its biomass, age and digestibility. Only above‐ground growth is modelled, using a light‐utilization efficiency approach modulated by a seasonal pattern of storage and mobilization of reserves. Ageing of plant parts is driven by cumulative thermal time from 1 January and by biomass flows. Age affects senescence, abscission and digestibility of green compartments and, therefore, the quality of green leaves and stems can increase or decrease over time in relation to net growth and defoliation dynamics. The functional traits having the greatest impact on model outputs are seasonal effects, period of reproductive growth and effects of temperature on photosynthetic efficiency. The functional traits of the grass groups were parameterized for temperate pastures of the Auvergne region in France. The other model inputs are few: proportion of functional groups, basic weather data (incident photosynthetically active radiation, mean daily temperature, precipitation and potential evapotranspiration) and site characteristics (nitrogen nutrition index, soil water‐holding capacity). In the context of a whole‐farm simulator, the model can be applied at a field scale.     

Preliminary studies on combiners and combinations for quality traits in tomato (Lycopersicon esculentum Mill.)

Line×Tester analysis of 2 testers and 10 lines was conducted for fruit quality characters. Though both general (gca) and specific combining ability (sca) variances contributed significantly for these traits, the contribution of sca variance was more prominent for titratable acidity, total soluble solids and ascorbic acid content, while for pericarp thickness gca variance was more important. The highest gca effects for pericarp thickness, total soluble solids, ascorbic acid content and titratable acidity were recorded by the lines SM, Sioux, TT and SW 72, respectively. Based on pooled gca score, SW 72 was recognised as a good combiner for quality traits. The magnitude and significance of sca effects varied with the characters. Two superior crosses were identified and the implication of combining ability effects on handling these crosses are discussed.     

玉米籽粒主要品质性状的分子遗传研究进展

玉米是全球最主要的粮食作物之一,提高玉米籽粒品质是当今世界玉米育种领域高度关注的问题。因为传统常规育种方法具有育种时间长且转化率低等限制因素,所以解决这一问题最经济有效的方法就是利用分子标记进行辅助选择育种。为了给今后玉米品质性状的分子设计育种提供参考,本研究总结了国内外玉米籽粒品质性状的QTL定位、分子标记辅助改良和候选基因克隆及转基因技术应用的相关研究进展。指出玉米优质基因资源的利用还不够充分,现有分子标记技术在玉米育种中的应用还不够广泛,今后应改进育种方法和品质鉴定技术,以缩短玉米育种周期。     

种植密度对北方设施叶用甘薯茎尖、产量和效益的影响

为探索北方地区设施叶用甘薯适宜种植密度,兼顾采摘难易和效益,在留有采收空间的前提下,设置6个密度（12万、15万、18万、21万、24万和27万株/hm²）,研究其对叶用甘薯茎尖性状、采收产量和效益的影响。结果表明：与12万株/hm²处理相比,15万、18万、21万、24万和27万株/hm²处理下,总采收量分别显著增加14.9%、19.4%、25.7%、20.5%、16.4%,21万株/hm²处理的产量最高;产量的增加源于平均采收茎尖数的增加,其中单次采收茎尖数的增幅在采收前期和中期较大,采收前期茎尖产量的增幅高于后期。随着密度的增加,单个茎尖平均鲜重逐渐降低,主要源于采收茎尖基部茎粗的降低。各处理下叶用甘薯净效益均较12万株/hm²处理增加,以21万株/hm²处理的净效益最高,增幅达30.1%。综合考虑,为兼具采摘和生产功能,在设施留有30 cm采收空间的条件下,种植叶用甘薯推荐21万株/hm²的密度,3行为一生产单元,留出采收空档,参考株行距18 cm×17 cm。     

不同育秧基质对水稻育苗的影响

[目的]了解4种不同水稻育秧基质对水稻秧苗农艺性状的影响,为水稻生产提供参考.[方法]采用稻壳、菌糠、混合(菌糠和稻壳同体积)、土壤(对照)4种不同育秧基质,测定水稻秧苗在不同生长期、不同基质的秧苗素质.[结果]不同育秧基质与对照(土壤)基质相比较,秧苗的株高、茎粗、叶绿素、光合速率、鲜重、干重等均无显著差异,其中菌糠和稻壳同体积混合基质中秧苗的综合素质最佳.[结论]稻壳和菌糠可作为育秧基质代替普通土壤,并且能够有效地节约生态资源.     

大豆主要农艺性状与产量相关性分析

[目的]为筛选参加山东省大豆区域试验生产试验品种提供参考。[方法]以2014、2015年2年山东省夏大豆生产试验品种为材料,对不同品种的主要农艺性状与产量关系进行相关性分析。[结果]试验结果表明,百粒重、节数与产量都呈负相关,单株荚数、单株粒数、分枝数与产量呈正相关,百粒重与单株粒数呈负相关。[结论]与对照相比,选择分枝数、有效荚、单株粒数比对照多,节数比对照少、百粒重略小的品种容易获得增产。