41份中晚熟欧洲玉米选系的配合力及杂种优势分析

试验以东北农业大学利用17份欧洲玉米种质选育的41份中晚熟优良自交系为材料,以代表瑞德类群的自交系D1798Z和兰卡斯特类群的HCL645为测验种,采用NCII遗传交配设计组配82个杂交组合,分析产量配合力及杂种优势关系。结果表明,41份欧洲选系的单株产量GCA相对效应值为-20.95%~26.72%,20份材料的一般配合力表现为正效应。DNF26-7-1、DNF03-12-2、DNP03-7-1等28份选系偏向于瑞德类群,DNF06-1-1、DNPA4-5-3-2、DN-2-12-1等13份选系偏向于兰卡斯特类群,其杂种优势模式为瑞德×兰卡斯特。18个杂交组合单株产量对照优势为正值,选系DNF14-9-2、DNR11-10-1和DNF26-6-1与HCL645组配的3个组合对照优势表现突出,育种潜力较大。     

甘蔗宿根性研究进展

甘蔗是我国重要的糖料作物。宿根蔗在甘蔗种植中占据极其重要的地位,选育宿根性强的品种是提高宿根蔗产量和品质的重要途径。本文综述了甘蔗的宿根性评价指标为:宿根能力与产量性状及效益相结合,综述了影响甘蔗宿根性内在因素主要有品种(基因型)和亲本(血缘),外在因素主要有土壤条件、肥水情况、收获时间、栽培措施和机械化收割等。介绍了适宜机械化生产的强宿根品种的选育情况,并对未来甘蔗宿根性的研究提出了:加强野生种质资源的开发利用、在逆境和机械收获条件下评价选育强宿根品种、加强全基因组选择评价及发株相关基因的研究挖掘等新技术新方法的应用研究。     

砒砂岩区主要造林树种枯落物持水性能及土壤物理性质

为揭示砒砂岩区主要造林树种枯落物持水性能及林下土壤物理性质变化特征,以位于黄土高原北部准格尔旗砒砂岩区6种林分类型为研究对象,运用浸泡法和烘干法,对林下枯落物、土壤(0—50 cm)的持水性能及物理性质进行研究。结果表明:(1)砒砂岩区6种林分类型林下枯落物厚度范围为0.73～2.77 cm,总蓄积量范围为1.47～7.93 t/hm~2。枯落物层厚度、总蓄积量大小依次为油松、侧柏、沙棘、柠条锦鸡儿、山杏和撂荒地。枯落物未分解层厚度及其蓄积量均明显大于半分解层。(2)林下枯落物最大持水率范围为149.48%～267.32%,枯落物最大持水率与有效拦蓄量大小顺序一致,为撂荒地柠条锦鸡儿沙棘山杏侧柏油松;枯落物最大持水量和有效拦蓄量均呈现出未分解层高于半分解层。(3)林下枯落物层在浸泡0.5 h吸水速率最快,浸泡1 h持水量增加迅速,浸泡8 h吸水速率和持水量增量趋近于0。(4)林下土壤容重低于撂荒地;总孔隙度范围为44.36%～32.57%,最大持水量范围为8.89～17.43 mm,均呈现油松林下最大,山杏林下最小。(5)林下枯落物蓄积量与土壤容重呈负相关关系,与土壤孔隙度、毛管孔隙度和非毛管孔隙度分别呈正相关关系。油松林、侧柏林地具有显著的保持水土能力。研究成果为开展砒砂岩区水土流失综合整治和生态修复提供了参考依据。     

Evaluation of the contribution of teosinte to the improvement of agronomic,grain quality and yield traits in maize (Zea mays)

Teosinte, an ancestor to modern maize, displays an excellent performance regarding resistance to stress, but its yield potential has rarely been reported. To evaluate the potential contribution of teosinte to maize improvement, two maize–teosinte backcrossed recombination inbred line (RIL) populations and their corresponding test-cross hybrids were planted for trait assessment. In RN and ZP RIL populations, the average coefficients of variation of 31 agronomic traits were 9.14% (Range, 0.38%‒25.21%) and 6.85% (Range, 0.55%‒27.73%), respectively. The correlation coefficients of 13 common shared traits between RIL populations and test-cross hybrid populations ranged from 0.10 to 0.60 and from 0.06 to 0.72, respectively. A total of 39 and 3 recombined inbred lines, and 29 and 47 test-cross hybrids exhibited higher yields than their checks (RP125, Zheng58, CD189 and ZD958) with the BLUP data, respectively. Furthermore, four test-cross hybrids including RN034/SCML1950, ZP068/Chang7-2, ZP079/Chang7-2 and ZP122/Chang7-2 showed a more stable yield performance, with yield gains of +7.07%, +3.64%, +5.83% and +3.82% over checks, respectively. In conclusion, teosinte could serve as an alien germplasm for maize breeding.     

成熟过程中细齿草木樨种子结构及产量和质量的变化

为了探索影响细齿草木樨(Melilotus dentatus Pers.)种子发芽力的主要因素，确定适宜的种子收获时间，本试验对不同成熟阶段细齿草木樨的种子结构、产量和质量进行了观察和测定。结果表明:随着细齿草木樨种子成熟，其栅栏细胞层厚度、骨状石细胞层厚度、硬实率、产量、千粒重和生活力呈上升的变化趋势，于完熟期达到最大值，其中硬实率与种皮栅栏细胞层厚度和骨状石细胞层厚度呈正相关；细齿草木樨种子的发芽势和发芽率呈先升后降的变化趋势，于黄熟前期后第5 d达到最大值；划痕后，细齿草木樨种子的发芽势和发芽率大幅提高，在完熟期分别由7.50%和8.00%增至96.00%和96.75%。综上所述，种皮硬实是影响细齿草木樨种子萌发的主要因素，其硬实程度可能取决于栅栏细胞层厚度和骨状石细胞层厚度。细齿草木樨在新疆阿拉尔市最适宜的种子收获时间为完熟期，用作播种材料时，必须先破除硬实。     

胡萝卜主要产量性状杂种优势及配合力分析

以３个不育系为母本，４个自交系为父本，按不完全双列杂交法配制１２个组合，进行杂种优势和配合力分析。结果表明，小区产量、单根重、根长和根粗均表现了明显的正向杂种优势，以小区产量和单根重的杂种优势较高；亲本一般配合力效应比组合特殊配合力效应更为重要，其中父本的作用大于不育系的作用；３０株系（Ｂ_３）小区产量、单根重、根长和根粗的一般配合力具有较大的正向效应值，丹富士分离株系（Ａ_２）心柱比例具有较大的负向效应值。从根形、根色及整齐度来看以丹富士分离株系（Ａ_１、Ａ_２）作母本，Ｂ_３为父本更为理想。     

白三叶分枝格局的研究

研究不同施肥处理对白三叶分枝格局和土壤利用强度的影响，结果表明，白三叶最合适的分枝角度为６０°，分枝能容忍的最大拥挤是４０°的扇形区域；整个克隆以源株为中心向四周生长形成六边形轮廓。同源株的分枝角度存在某种调节机制，施肥对新形成的分枝角度有微调功能。低施肥处理时，白三叶表现“利用策略”；高施肥处理时，植株表现“占居策略”。     

Effects of Competition upon the Productivity of White Clover-Perennial Ryegrass Mixtures. Genetic Analysis

A diallel cross amongst four contrasting white clover varieties was used to provide genetic information on those characters which affect the productivity of white clover-perennial ryegrass mixtures when grown under a cutting-only management regime. Generally speaking those characters recorded on the clover families and in mixtures exhibited highly significant additive and non-ad dative genetic effects, though for1 sortie characters the latter could not be ascribed solely to dominance effects. For two of the clover characters, stolon and leaf number, the genetic picture was radically altered in mixtures by the effects of inter-specific competition Pseudo-genetic effects were also detected for the grass characters, bur it was suggested that the two ryegrass varieties used here were exhibiting phenotypic plasticity. As a group the four intra-varietal crosses performed significantly better than the six intra-varietal crosses for all clover and mixture characters. Only one of the inter-varietal crosses had significantly positive specific combining ability effects for most characters and that was between the two long established varieties ‘S. 184’ and ‘S. 100’. The implications of these results for the breeding of white clover varieties for use in mixtures are briefly discussed.     

Specific and General Adaptation and Yield Stability of Wheat (Triticum aestivum L.) Genotypes

Mean grain yield performance of 12 wheat and one triticale genotypes were measured at four locations over four consecutive years, using a randomized complete block design with four replications. The genotypes used were commercial cultivars and advanced lines from different wheat breeding projects located in different areas in Iran. Two locations were in semiarid regions and the other two locations in the temperate zones. The combined analysis of variance indicated highly significant genotype-environment (GE) interactions. From combinations of locations and years three sets of environments were generated. Set I and set II, each, consisted of eight environments (two locations and four years) representing semiarid and temperature environments, respectively. Set III consisted of 16 environments including both semiarid and temperate conditions. Set I and set II were used to measure specific adaptation of the genotypes while set III was employed for measuring general adaptation. The methods of Eberhart and Russell (1966) were used for partitioning GE interactions. The mean square associated with the heterogeneity of regression was highly significant under all sets of environments. These observations indicated that a major part of GE interaction could be accounted for by differences in the regression of the individual genotypes. All the genotypes had significant regression mean square under set I, set II, and set III environments, with the exception of two genotypes under set II. However, mean yields, regression coefficients, and the mean squares associated with deviation from regression greatly varied over the sets of environments. Only three genotypes, a commercial cultivar and two new advanced line, were identified as having specific adaptation and yield stability to semiarid environments. Among all the genotypes, only a commercial cultivar was identified as adapted and stable to temperate conditions. Two of the three genotypes which were adapted to semiarid environments also showed general adaptation to set III environments. However, the mean yield of these two genotypes under semiarid conditions (set I) were significantly greater than their respective mean yields under set III environments. Thus, wider adaptability was compensated by lower mean yield. The present study indicates that, while a wide range of environments is necessary and recommended for measuring general adaptation reactions and yield stability of various genotypes, one should not ignore the possibility of finding some genotypes with specific adaptation to specific environments and thus maximizing yield production. Stable genotypes with general of specific adaptation should be utilized in breeding projects in order to develop even more desirable lines.