16个糖能兼用甘蔗品种（系）种性比较

为了解不同糖能兼用甘蔗品种（系）的种性和生产性表现,为今后进行能源甘蔗品种选育和推广提供参考,以广西主栽甘蔗品种ROC22、ROC16作对照,对来自国内外的16个品种（系）在2种不同类型土壤蔗区进行2年新植1年宿根种性比较试验。结果表明 B1、B8、GT26、GT02/833、B9、B28、GT02/48、GT97/69、GT02/208等品种（系）在生物产量、蔗茎产量、蔗糖产量和总可发酵糖产量等方面明显超过对照种ROC22、ROC16,具有丰产性好、抗逆性强、适应性广的优良种性,可在广西的旱地和水田蔗区既可作糖料蔗,也可做能源蔗种植利用。YT96/86、GT99/156和FN94/0403综合表现一般,可在桂南的水田蔗区因地制宜种植。其余品种（系）表现较差,不宜在广西扩大种植和推广。     

Efficiency of border rows in replicated sugar cane variety trials

Summary Each row was weighed separately in 34 sugar-cane variety trials harvested from 1973 to 1976. The efficiency of weighing only the middle row(s) compared with the whole plot was estimated by calculating coefficients of variation and theoretical gains from selection.It was not efficient to weigh only the middle row in trials with 3-row plots. Gain from selection for true yield (that is, yield in the absence of competition from other varieties) was reduced by 7% and the coefficient of variation increased by 4%, this representing an increase of about 33% in the variability of the trials.It was efficient to weigh only the middle two rows of 4-row plots, especially for trials on commercial farms. This gave a 2% increase in gain from selection and the coefficient of variation was increased by only 0.9%. It reduces the weighing time and amount of cane weighed, minimizing the delay to commercial harvesting while trials are being weighed.On Experiment Stations where land is a limiting factor, the most efficient method is to continue the present practice of planting 3-row plots and weighing the whole plots.     

A technique for minimising confounding of genotype x year and genotype x crop type effects in sugarcane

Summary Genotype x year (G x Y) and genotype x crop (G x C) interactions may be confounded in sugar cane when data is obtained from the plant crop and/or from ratoon crops in successive years. A technique to minimise the effects of confounding of the G x C interaction with the G x Y interaction is presented. The mean yield of cane from neighbouring farms was used as an indicator of the year (environment) effect. It was used to re-analyse yields from three experiments comparing six genotypes grown over a plant crop and three ratoons. Two experiments were grown under rainfed conditions and one experiment was irrigated. The confounded interactions were partitioned into a linear contrast on the farm yields (a year effect) and a crop effect that was the remainder. When the yields adjusted for the farm yield effects were compared with original yields of cane, yields of plant and first ratoon were reduced and those of third ratoon were increased. There were only minor changes in the ranking of genotypes on yield. It was concluded that the re-analysis using farm yield showed that the confounding effect of years on the interpretation of genotype x crop effects was samll.     

Efficiency of bunch-planted and single-planted seedlings for selecting superior families in sugarcane

Summary The efficiency of family selection in bunch-planted sugareane seedlings was investigated by planting 40 families (20 proven and 20 experimental) as bunches and as single seedlings in adjoining replicated trials. A replicated trial planted the following year. using stem cuttings from random seedlings of each family. provided an independant estimate of the value of each family.Five methods were used to compare bunch and single planting, namely theoretical and realized gains from selection, correlations between the seedling and evaluation trials, discrimination based on proven cross classes, and discrimination based on production of advanced selections. Overall, bunch planting was inferior to single planting for family selection. It was promising for only one method of evaluation (proven cross classes) but this, combined with the relatively small area required for bunch-planted seedlings, indicates that family selection may be possible in such plantings. The use of a number of methods of evaluation showed that incorrect conclusions were likely if only one method were used, and revealed deficiencies in methods which would otherwise be considered satisfactory. The project provided a basis for the design of more critical experiments.The components of weight of cane, namely number of stalks and weight per stalk, are negatively correlated, and showed different relationships with yield in the seedling and evaluation trials. Weight per stalk was an important component in seedling trials, with number of stalks by far the main component in the evaluation trial which was planted by the commerical method using stem cuttings.Family selection based on number of stalks and sugar content, preceding mass selection, is likely to provide a better selection system than the usual mass selection in bunch-planted seedlings.Families do not express their full genetic potential in original seedlings. whether bunch or single planted: trials planted from stem cuttings give more effective family selection. Furthermore, family selection for the most important characters (net merit grade and weight of sugar) was much more effective in ratoon than in plant crops. These results have important implications for the practical selection program, further experimental work being necessary to specify the most efficient system.     

Inter-relationships among total crude protein and digestible dry matter production and their component traits in Guinea grass

Summary Phenotypic and genotypic correlation coefficients of total crude protein per plant (TCP) and digestible dry matter per plant (DDM) with dry matter yield per plant (DMY), tiller number, plant height, stem thickness and leaf-stem ratio, pooled over two years, revealed that TCP and DDM were correlated at both the phenotypic and genotypic levels with DMY, tiller number and plant height. But only DMY had high direct effects on TCP and DDM. Tiller number and plant height had only indirect effects on TCP and DDM via DMY. Thus, selection based on tiller number and plant height may not only improve dry matter yield per plant but also total crude protein per plant and digestible dry matter per plant. Further, screening of high TCP and high DDM clones among the high yielding clones would be a more remunerative approach to improve TCP and DDM in Guinea grass.     

粤糖系列甘蔗品种产量因子间相关和通径分析

以粤糖系列10个甘蔗品种的历年选育试验数据为材料,利用相关分析、多元回归、通径分析和决定系数等方法,分析蔗茎产量与其构成因子的密切程度,以及各因子对产量的相对贡献大小。简单相关分析结果表明,蔗茎产量与有效茎数和茎长呈极显著正相关(0.643**和0.650**),与茎径相关不显著(0.025),有效茎数和茎长呈极显著正相关(0.234**),茎径与有效茎数和茎长呈极显著负相关(-0.416**和-0.257**);偏相关分析结果表明,蔗茎产量与其构成因子都呈极显著正相关(0.854**、0.836**和0.741**);多元回归方程为y=0.235x1+0.370x2+48.795x3-202.674 (ry.123=0.924**),F值均达到极显著水平;通径分析和决定系数分析结果表明,有效茎数对蔗茎产量的直接效应和直接决定系数都最大(0.696和0.485)。以上分析都表明,相对于茎长和茎径,有效茎数与蔗茎产量关系最密切,对蔗茎产量的贡献最大,增加有效茎数可显著提高蔗茎产量。有效茎数是影响蔗茎产量的关键因素,是品种高产选育和高产栽培的主攻方向,甘蔗高产育种中,应首先考虑对有效茎数的选择,其次考虑对茎径和茎长等影响蔗茎产量重要因素的选择。     

作物产量性状QTL定位的研究现状及应用前景

作物的许多农艺性状和经济性状是数量性状。研究作物数量性状遗传对农作物育种具有十分重要的意义。本文综述了数量性状基因座QTL（quantitative trait locus）定位的原理和常用方法及分子标记在水稻、小麦、玉米、棉花、大豆、番茄、大麦和油菜等重要作物产量性状基因定位中的研究现状,并对目前产量性状QTL定位存在的问题和发展前景进行了探讨     

Use of component analysis in QTL mapping of complex crop traits: a case study on yield in barley

Genes contributing to the quantitative variation of a complex crop trait can be numerous. However, using existing approaches, the number of quantitative trait loci (QTL) detected for a trait is limited. Therefore, rather than looking for QTL for a complex trait itself, determining QTL for underlying component traits might give more information. In this study the potential of component analysis in QTL mapping of complex traits was examined using grain yield in spring barley as an example. Grain yield was divided into three components: number of spikes/m², number of kernels/spike, and 1000‐kernel weight. These traits were measured for individuals of a recombinant inbred‐line population in field trials conducted over 2 years. By the use of an approximate multiple QTL model, one to eight QTL were detected for each trait in a year. Some QTL were mapped to similar positions in both years. Almost all QTL for yield were found at the position of or in close proximity to QTL for its component traits. A number of QTL for component traits were not detected when yield itself was subjected to QTL analysis. However, relative to the QTL for yield itself, all component‐trait QTL did not explain the variation in yield better. The results in relation to the potential of using component analysis in studying complex crop traits are discussed.     

Variance component analysis of plant architectural traits and fruit yield in melon

Summary  A cross was made between a unique highly branched, early flowering line, U. S. Department of Agriculture (USDA) 846-1 (P_1; 7 to 11 lateral branches), and ‘Topmark’ (P₂; 2 to 4 lateral branches), a U.S. Western Shipping melon, to produce an array of 119 F₃ families. Subsequently, a genetic analysis was conducted at Arlington and Hancock, Wisconsin in 2001 to evaluate the segregating progeny for factors likely involved in yield-formation, including days to anthesis, percentage of plants with early pistillate flowering, primary branch number, fruit number and weight per plant, average weight per fruit, percentage of plants with predominantly crown fruit set, and percentage of plants with early maturing fruit. Although, genotype × environment (G × E) interactions were important for some traits (e.g., fruit number and fruit weight), considerable additive and/or dominance variance was detected for all traits. This research provides critical data associated with highly branched melon germplasm including trait correlations and heritabilies (broad- and narrow-sense ranged between 0.28 and 0.91) that used judiciously will allow the development high yielding melon cultivars with early, basally concentrated fruit suitable for once-over or machine harvesting operations.     

Limited contribution of water availability in genotype-by-environment interaction in sugarcane yield and yield components

Water deficit is an important abiotic stress factor limiting sugarcane production. Understanding the effect of water deficit on cane yield, yield components and genotype × environment (G × E) interaction can aid in selecting genotypes that are adapted to water deficit conditions. In this study, response of cane yield and yield components of 10 sugarcane genotypes grown under 3 irrigation treatments—fully irrigated, semi-irrigated and rainfed—was examined across 3 locations and 3 crop-years within each location. Cane yield reduced by 32% and 9% in the rainfed and semi-irrigated treatments, respectively, compared to the fully irrigated treatment. Genotypic variation was highly significant for cane yield and yield components in all three irrigation regimes. Cane yield in the rainfed treatment showed significant genetic correlation with stalk diameter (r_g = 0.68), leaf number (r_g = 0.64), node number (r_g = 0.67) and stalk number (r_g = 0.68). Genotype × irrigation variance was negligible compared to genotype, genotype × location and genotype × crop-year variances. Commercial genotypes had higher yield in most environments except in low-yield potential environments, which caused a significant genotype × location × irrigation effect, suggesting opportunities for improving sugarcane productivity in these environments.     

秸秆还田结合秋覆膜对旱地冬小麦耗水特性和产量的影响

秸秆还田和秋覆膜是西北旱地雨养农业区冬小麦生产中有效的节水增产措施。为明确西北半干旱雨养农业区不同作物秸秆还田结合秋覆膜种植模式下冬小麦田土壤蓄水保墒和节水增产效果,于2011年9月至2013年6月连续2个小麦生长季在甘肃省通渭县进行了田间定位试验,比较玉米秸秆还田结合秋覆膜、单一玉米秸秆还田、麦秸秆还田结合秋覆膜、单一麦秸秆还田和传统平作种植对西北旱地冬小麦耗水特性和籽粒产量的影响。结果表明,与传统平作相比,冬小麦全生育期秸秆还田结合秋覆膜处理0～200 cm平均土壤贮水量在2011—2012和2012—2013年度分别提高6.1%和9.6%,而单一秸秆还田分别提高0.7%和4.6%。在降水偏多的2011—2012年度,除玉米秸秆还田结合秋覆膜处理冬小麦全生育期0～200 cm土壤贮水消耗量比传统平作低19.0 mm (P0.05)外,其余各处理无显著差异;在降水偏少的2012—2013年度,秸秆还田及秸秆还田结合秋覆膜处理平均比传统平作多耗水39.1 mm,其中,两个秸秆还田结合秋覆膜处理显著增加冬小麦返青至拔节阶段的耗水量,显著降低开花至成熟阶段耗水量,并增加了对深层土壤水分的调用。与传统平作相比,秸秆还田结合秋覆膜处理可使小麦籽粒产量提高31.0%～69.4%,水分利用效率提高25.6%～43.0%;而单一秸秆还田的小麦籽粒产量提高1.2%～28.0%,水分利用效率提高3.0%～11.6%。以玉米秸秆还田结合秋覆膜处理增产效果最好,2年平均籽粒产量和水分利用效率分别较传统平作提高51.1%和41.7%,且显著高于其他处理。因此,玉米秸秆还田结合秋覆膜种植模式能显著提高冬小麦籽粒产量和水分利用效率,适宜在西北旱农区小麦生产中应用。     

Environmental correlations among grain yield and other important traits of wheat in drylands

Summary Environmental correlation coefficients were computed among all pairs of five traits, namely grain yield, heading date, number of tillers per m², plant height and 1000-grain weight (grain size) using 30 Triticum durum and 30 Triticum aestivum varieties grown in 18 environments. Grain yield was significantly correlated with the other four traits in almost all of the varieties. The mean correlation coefficient over all varieties ranged from 0.58 to –0.83 for durum wheat and 0.66 to 0.88 for aestivum wheat. The correlation coefficients between heading date and the other traits were also significant, ranging from –0.45 to –0.79 in durum wheat and –0.61 to –0.85 in aestivum wheat. The correlation coefficient between number of tillers with plant height and 1000-grain weight were the smallest, 0.19–0.32 in durum wheat and 0.39–0.60 in aestivum wheat. It was concluded that agronomic practices favouring early and good stand establishment in the dry regions will favour the yield components and important adaptive traits, which contribute towards larger yields. Significant differences were found among genotypes in the environmental correlation coefficients and the associated changes in one trait as a result of changes in other traits.     

Genetic dissection of the relationship between plant architecture and yield component traits in soybean (Glycine max) by association analysis across multiple environments

Plant architecture and yield components are critical for the determination of seed yield in soybean. In this study, we performed genetic association analysis to dissect the relationships between plant architecture and yield component traits. Two hundred and nineteen accessions were employed, and eight agronomic traits were evaluated in six environments. Our results revealed strong positive correlations of plant architecture traits with yield components and the significant association of 4 SNPs with plant architecture traits and of 7 SNPs with yield component traits in two or more environments. Eight SNPs were co‐associated with two traits. Based on the phenotypic effects of the alleles of the detected SNPs, the best alleles were mined for twenty‐three distinct SNPs. Fifteen typical carrier materials harbouring the best allele effects were also mined. Twenty parental combinations were proposed by pyramiding possible alleles per SNP in one individual (excluding possible epistatic effects). These proposed combinations with the best alleles and carrier materials will aid in the improvement of targeted traits and marker‐assisted selection (MAS) efficiency in soybean breeding.     

Heritability of, and genetic correlations among, forage and seed yield traits in Ladino white clover

Sixteen white clover genotypes and their half-sib progenies were grown in pure stand. Each clover progeny was also grown in a mixed stand that also included three grass varieties of different species. Dry matter (DM) yield was measured over 2 years and seed yield at the second year. Competitive ability of clover families was defined as the ratio between mixed stand and pure stand for clover DM yield. Narrow-sense heritability from parent-offspring regression of pure stand data was high to moderate (h²0.50) for DM yield, seed yield and most of their components. Persistence as predicted by stolon density showed negative genetic correlations with seed yield (r_g= -0.70) and DM yield (r₂= -0.60), whereas seed yield and DM yield tended towards a negative correlation (r₂=0.45). Sizes of different vegetative or reproductive organs were generally correlated positively. Evidence was provided that the set of parent genotypes represents well the genetic variation available within the Ladino gene pool. The results highlighted the difficulty of combining relatively short-term DM yield, persistence and seed yield into a unique plant type. Differences in competitive ability emerged only in the second year, better ability being related mainly to petiole length among the traits assessed in pure stand.     

Genomic prediction of grain yield in commercial Finnish oat (Avena sativa) and barley (Hordeum vulgare) breeding programmes

Genomic selection has been adopted in many plant breeding programmes. In this paper, we cover some aspects of information necessary before starting genomic selection. Spring oat and barley breeding data sets from commercial breeding programmes were studied using single, multitrait and trait-assisted models for predicting grain yield. Heritabilities were higher when estimated using multitrait models compared to single-trait models. However, no corresponding increase in prediction accuracy was observed in a cross-validation scenario. On the other hand, forward prediction showed a slight, but not significant, increase in accuracy of genomic estimated breeding values for breeding cohorts when a multitrait model was applied. When a correlated trait was used in a trait-assisted model, on average the accuracies increased by 9%–14% for oat and by 11%–28% for barley compared with a single-trait model. Overall, accuracies in forward validation varied between breeding cohorts and years for grain yield. Forward prediction accuracies for multiple cohorts and multiple years’ data are reported for oat for the first time.     

旱地全膜双垄沟播秋覆膜对玉米产量和水分利用率的影响

在推广应用旱地玉米全膜双垄沟播栽培技术基础上,从进一步减少冬春季土壤水分的无效蒸发、提高土壤含水量、改善玉米经济性状、提高玉米产量入手,进行了全膜双垄沟播秋覆膜对旱地玉米产量和降水利用率影响的试验研究。结果表明,全膜双垄秋覆膜沟播栽培可明显减少冬春季土壤水分的无效蒸发、增加土壤水分含量、玉米的经济性状明显改善,玉米产量比全膜双垄沟播栽培播种前覆膜和半膜覆盖栽培分别增产16.13%和46.08%,增产效果明显;水分生产率比全膜双垄沟播栽培播种前覆膜和半膜覆盖栽培分别提高34.5%和57.8%。     

The stage sensitivity of short‐term heat stress to lodging‐resistant traits and yield determination in canola (Brassica napus L.)

With the expected increase of abiotic stress under global climate change, significant research has been devoted to how abiotic stress will affect crop production. To date, there has been little research on the stage sensitivity of short‐term heat stress to crop lodging and yield determination in canola. This research was conducted in a controlled growth facility and aimed to examine root morphology, pod fertility, seed yield and crop lodging of two contrasting canola genotypes subjected to a short‐term heat stress (27.0/24.3°C, light/dark), imposed respectively at three growth stages, rosette vegetative stage (RVHT), early flowering stage (EFHT) and late flowering stage (LFHT), in comparison with non‐stressed control (CK) (23/17°C). The results demonstrate that heat stress imposed at RVHT and LFHT was less detrimental to seed yield and lodging resistance. However, EFHT showed significant adverse effects on both, which was further confirmed by redundancy analysis (RDA) and structural equation modelling (SEM). Compared with the CK, EFHT resulted in a yield loss of 43%, which was mainly due to poor pod fertility, less number of filled pods (?28%), decreased pollen viability (?38%) and a lower success ratio of filled pods (?29%). The taproot was found to be relatively tolerant to heat stress, but lateral roots were sensitive to heat stress at EFHT and LFHT. Root capacitance could be used as a non‐destructive method for evaluating lateral root morphology. Compared with the CK, EFHT displayed a high risk of stem lodging, as indicated by a 27% lower safety factor. This was mainly attributed to the reduced stem bending strength that was caused by the deterioration of stem mechanical properties under EFHT, as illustrated by SEM. Root lodging resistance was not altered by any stages of short‐term heat stress, as the taproot remained stable.     

春马铃薯种薯大小对其植株性状及产量的影响研究

该文选用过翻秋的小整薯作种进行春播试验，探讨了不同大小种薯对植株性状和产量的影响及其经济效益。结果表明，从植株性状和产量上看，每窝种薯数在１－４范围内，随着种薯数的增加，每窝基本茎数增加，出苗后第３０天冠层覆盖度增加，株高降低，茎粗变细，结薯数增加，埠茎产量变化不大，单个块茎重减少，大中薯数变化不多，大中薯重下降，大中薯数率和大中薯重率降低，其中每窝和薯数与基本茎数，出苗后第３０天的冠覆盖，株高，     

Genetic progress after four cycles of recurrent selection for yield and grain traits in common bean

The objective of this study was to evaluate the genetic progress after four cycles of recurrent selection in common bean. The base segregating population was obtained from 10 parents, and derived the S_0:1 and S_0:2 families that were evaluated. The S_0:3 families with higher grain yield and grain color, like the standard carioca were selected, and were intercrossed to generate the population of the following cycle. This process was repeated for four cycles. The best families were evaluated in each cycle by many generations and locations, and the five best lines of each cycle were identified. The 20 lines thus obtained were evaluated in two growing seasons, sown in July and November 2002. The grain yield (kg/ha) and grain type (scale of scores) were evaluated. Genetic progress was confirmed for both traits. The mean annual gain with selection for the grain type was 10.5% and 5.7% for grain yield, with no evidence of variability reduction in the population. These results show that recurrent selection is a good alternative for improving common bean quantitative traits.     

Seed yield related to crop development and to yield components in nine cultivars of perennial ryegrass (Lolium perenne L.)

Summary We had previously found differences for seed yield among nine perennial ryegrass cultivars which were not associated with variation for seed weight. To detect the physiological basis of these genetic differences for seed yield, growth analyses were carried out. We related crop development and components of seed yield to seed yield during three years on clay and sandy soil. No significant differences occurred among cultivars for accumulation and partitioning of dry matter or the pattern of tiller production. Seed yield of the cultivars was not associated with ear number or total dry matter yield of the seed crop. Seed yield was more correlated with the number of seeds per unit area than with seed weight. The number of seeds as calculated after harvest from seed yield and seed weight was much lower than the number of seeds as estimated prior to harvest from seed yield components. The number of spikelets differed significantly among the cultivars, but the ranking was different from that for seed yield. The physiological basis of the genetic differences for seed yield is not clear. Implications for breeding perennial ryegrass are discussed.