Lodging Resistance Related to Root Traits for Mechanized Wet-Seeding of Two Super Rice Cultivars

Mechanical hill wet-seeded rice machine is beneficial for establishing and growing uniform rows of seedlings.However,there is limited knowledge regarding the effects of the establishment of furrows on growth,lodging and yield,and their relationships with root traits.In this study,field experiments were conducted during 2012 and 2013 using two super rice varieties(hybrid rice Peizataifeng and inbred rice Yuxiangyouzhan)under three furrow establishment treatments(T1,both water and seed furrows were established by the machine;T2,only seed furrows were established by the machine;and T3,neither water nor seed furrows were established by the machine).Lodging index,lodging-related traits,grain yield,above-ground dry weight and root traits were measured.The results showed that the lodging index was significantly affected by the treatments with furrows(T1 and T2).The strongest lodging resistance was detected in the mechanical hill wet-seeded rice with furrow treatment(T1)in both 2012 and 2013.Lodging resistance was strongly related to the breaking resistance.No significant difference was found in grain yield or dry weight of the mechanical hill wet-seeded rice.Therefore,the mechanical hill wet-seeded rice with furrow treatment increased rice lodging resistance,which was related to root traits.     

The Power of Integrative Approaches to Develop Markers for Maize Molecular Breeding

Recent advances in genomics and bioinformatics now offer real opportunities for dissecting complex Waits into their component sub-traits, which will simplify the process of developing the tools necessary to manipulate the underlying genes （Varshney et al., 2005）. The value of molecular markers as a complement to phenotyping under several breeding scenarios is largely unquestioned, as demonstrated by the increasing number of successful studies published （Varshney et al., 2006）. However most experiments have targeted crop improvement for disease resistance, morphological waits or quality waits （Franca et al., 2005） and there is still some way to go before markers can be used routinely and ubiquitously to breed for complex waits, such as tolerance to abiotic stress （Ribaut and Ragot, 2007）. The combination of genetic mapping and association studies has considerable potential to generate a catalogue of genetic variation, and thereby present novel opportunities for selection based on genome-wide scans （Biswas and Akey, 2006）. Nevertheless, it remains to be seen whether the outcome of gene interactions, particularly where significant gene networks are involved,     

Dissection of Wheat Breeding in China by Marker/Trait Association

Besides the natural selection, the crops cultivated today have experienced two episodes of strong artificial selection, domestic and modem breeding. Domestication led to giant genetic structure differentiation between cultivars and their wild species, while modem breeding made further genetic structure differentiation between the modem varieties and the landraces. In a population, diversity of the loci under strong selection is significantly lower than that of other loci. At the same time, diversity in the genomic regions flanking these selected loci also declines in the process of selection. This phenomenon is called hitchhiking effects or selection sweep in genetics （Andolfatto, 2001）.     

电子束辐射羽衣甘蓝红鸥干种子对植物性状的影响

利用不同剂量的电子束辐照羽衣甘蓝红鸥成熟干种子,探索电子束辐照对其植株生长性状的影响,结果表明,电子束辐照对羽衣甘蓝红鸥的生物学性状的影响不明显,但对栅栏组织解剖结构的厚度、植株株高和叶绿素b含量的影响达到显著水平,同时提高了植株的抗病虫害能力,提早了M1的花期。     

中国不同地带性森林乔木叶片热值特征及其影响因素

[Objective]To study the leaf calorific value of different forest types.[Method]This study focused on four common forest types widely distributed across China, including boreal coniferous forest, warm temperate deciduous broad-leaved forest, subtropical evergreen broad-leaved forest, and tropical monsoon forest. The leaf calorific values of 175 dominant (or common) tree species were measured. The leaf calorific value characteristics of the trees found in the different forest types were analyzed, and the primary factors affecting leaf calorific value were investigated, including leaf morphological traits, nutrient elements, climate, and soil traits. [Result]The results showed that in these forest types, the leaf calorific values ranged from 14.84 to 21.98 KJ·g^-1, with an overall mean of 19.06 KJ·g^-1. The presence of organisms appeared to affect the leaf calorific value, which differed among forest types as follows: coniferous trees > broadleaf trees or evergreen trees > deciduous trees. [Conclusion]The latitudinal pattern of tree leaf calorific value, ordered from north to south, is as follows: warm temperate deciduous broad-leaved forest > subtropical evergreen broad-leaved forest > tropical mountain rainforest. The mean leaf calorific value of boreal coniferous forest was slightly lower than those of warm temperate deciduous broad-leaved forest and subtropical evergreen broad-leaved forest. The leaf calorific values were significantly correlated with leaf carbon content (R²= 0.89, P<0.001). A multiple regression equation was established to describe the relationships among leaf calorific value, leaf carbon content, leaf nitrogen content, and leaf thickness.     

黄粉虫蛹不同温度处理对人工繁育川硬皮肿腿蜂的影响

为了探究黄粉虫蛹不同温度处理对人工繁育川硬皮肿腿蜂的影响,该研究设置了5个处理温度(-10,-4,0,4,10℃)和3个处理时间(1,4,7d)。通过比较川硬皮肿腿蜂在不同处理蛹上的寄生率、繁蜂成功率、单管繁蜂量和出蜂效率4个繁育指标,筛选最适于繁蜂的寄主处理温度和处理时间。试验结果表明,相较于对照组,低温处理能够显著提高川硬皮肿腿蜂的繁殖效率。其中-4℃处理黄粉虫蛹7d后繁育的川硬皮肿腿蜂的寄生率、繁蜂成功率、单管繁蜂量和出蜂效率均显著高于其他处理,分别为76.67%,66.67%和8.15,10.89头,可显著提高川硬皮肿腿蜂的繁育效果。因此,推荐以-4℃处理黄粉虫蛹7d为最佳处理。     

合浦珠母贝家系的建立及生长性状的比较

以经过连续2代群体选育的合浦珠母贝为亲本,采用雌雄单个配对的方法,建立了10个合浦珠母贝家系,对家系的生长性状进行了比较研究。结果表明,壳长的大小顺序为F2>F7>F1>F10>F4=F5>F9>F6>F3>F8;壳宽的大小顺序为F5>F2>F1>F7>F4>F10>F9>F6=F8>F3;壳高的大小顺序为F2>F1>F5>F10>F4>F7>F6>F9>F8>F3;总重的大小顺序为F2>F1>F5>F7>F10>F4>F6>F8>F9>F3。在该批家系中,F2的壳长、壳高、总重均为最大,壳宽虽然小于F5,但无显著性差异,因此认为该家系具有较强的生长优势,可作为进一步选育的材料。通过分析发现,F1、F5家系的各个生长指标总体生长都较快,因此F1和F5家系也具有一定的生长优势,也可以选作为进一步选育的材料。     

黑龙江省玉米品种农艺性状与单株粒重的灰色关联分析

选取黑龙江省中、晚熟玉米对照品种及杂交组合共160份,采用灰色关联分析方法,对影响玉米产量(单株粒重)的主要农艺性状进行研究。结果表明,与玉米单株粒重相关的农艺性状中,穗粗、百粒重和穗长最为重要,整体关联度排序为:穗粗>百粒重>穗长>生育期>行粒数>吐丝期>散粉期>穗位>株高>穗行数>出苗期>出籽率,这说明目前玉米新品种选育应以果穗粗、长,百粒重大且穗行数多为主,以其他农艺性状适中为目标,协调各相关因素,提高产量。本试验利用大量品种(组合)明确玉米主要农艺性状对产量的贡献,为选育高产玉米新品种提供了理论参考依据。     

新质源(CMS-FA)杂交稻产量相关性状的相关性分析

以新质源(CMS-FA)杂交稻遗传系统的5个不育系和5个恢复系进行不完全双列杂交,采用加性一显性遗传模型和MINQUE (1)法,对新质源(CMS-FA)杂交稻产量相关性状进行多种相关分析.结果表明,新质源(CMS-FA)杂交稻产量相关性状间的相关性为;株高与结实率,剑叶长与生育期、结实率,生育期与每穗实粒数,结实率与千粒重,千粒重与单株产量等性状之间的遗传相关以基因的加性正相关为主;单株穗数与株高、剑叶长、每穗总粒数、每穗实粒数、结实率,千粒重与每穗总粒数等性状之间的遗传相关以基因的加性负相关为主.株高与穗长、剑叶长、每穗总粒数、千粒重,穗长与每穗总粒数,每穗实粒数、单株产量等性状之间具有显著或极显著的显性相关.利用加性相关为主的性状进行间接选择可取得较好的育种效果.     

基于Cox半参数模型检测生存性状的印记数量性状位点

在生存分析中,Cox比例风险模型和加速失效模型是研究控制数量性状位点(QTL)的生存时间的常用的方法。本文首先借助于Cox比例风险模型给出了半参数的区间定位方法去表征生存性状的印记数量性状位点(iQTL)。此方法的明显优势是无需估计复杂的"讨厌"的基线风险函数。然后构造偏似然函数并根据其推断出iQTL的参数估计。采用期望最大化算法求解iQTL位置和遗传效应的极大似然估计值。所给统计推断方法保证了整个基因组范围内的显著iQTL的估计和检验,在一系列的零假设下,给出了所检测到的iQTL的印记模式。最后,此方法应用于分析一个公开发表的小鼠模型系统数据集。