大豆种质资源农艺性状和产量的年份间差异及其关系

明确大豆种质资源农艺性状的变化及其与产量的关系对大豆遗传育种具有重要的意义。以249份大豆种质资源为材料,应用多元统计方法分析了大田条件下两年间大豆农艺性状与产量的变化。结果表明,大豆种质资源的农艺性状和产量两年变异系数分别为6.2%~78.0%和6.3%~48.5%,变异较大。生育日数因在黄淮海区域生态类型较接近,变异系数较小;而主茎节数变异系数也较小。株高、有效分枝数、底荚高度、单株荚数、单株粒数、每荚粒数、单株粒重、百粒重、单位面积产量则相对变异较大。品种之间农艺性状和产量差异均显著。不同年份间生态因子（温度、降水量及日照时数）对大豆农艺性状和产量的影响较大,年份间不同指标差异亦显著。分别对两年农艺性状采用主成分分析,简化为4个与产量相关的独立指标,并建立了产量与农艺性状之间的方程Y=17.5-1.76x1+1.32x2+0.30x3+2.50x4和Y=198.8-3.12x1+7.71x2+0.08x3+2.71x4以表达其量化关系;采用聚类分析方法将两年中249份大豆种质资源分别聚为5类,并分析了各类品种的特性,为高产稳产大豆新品种的选育以及高产栽培措施的调控提供理论依据。     

甘蓝型油菜育种亲本单株产量与农艺性状相关性分析

油菜是我国重要的油料作物,提高油菜产量是油菜育种的首要目标之一。油菜育种中,考察和分析油菜种质的主要农艺性状是筛选育种亲本材料配制优良组合的前提基础,可以为高效开展重要性状的改良提供有效的科学依据。以213份长江流域油菜主产区育种单位提供的甘蓝型油菜育种亲本为材料,采用相关分析、通径分析、多元回归分析及主成分分析等方法,探讨在成都平原气候条件下,油菜单株产量与10个相关农艺性状之间的关系,明确甘蓝型油菜产量形成的主要决定因子。结果表明,不同地区油菜资源农艺性状存在较大差异;单株产量与株高、主序有效长度、一次有效分枝数、主序有效角果数、角果长度、每角果粒数和千粒重呈极显著正相关,与营养生长天数呈显著负相关;对单株产量直接影响最大的是株高,其次是每角果粒数和一次有效分枝数,间接作用最大为主序有效长度,其次是主序有效角果数和一次有效分枝高度。逐步回归分析表明,株高、每角果粒数、一次有效分枝高度和一次有效分枝数是决定单株产量的主要因子;通过主成分分析,可将相关性状综合为4大类:株高控制因子、生育期控制因子、产量性状控制因子和株型控制因子。本生态区域内决定产量形成的关键性状为株高、每角果粒数、一次有效分枝高度和一次有效分枝数,本研究得出的结果对于充分利用各育种单位亲本材料优良性状提供了有价值的参考。     

甘蓝型油菜-白芥渐渗系材料农艺性状和种子品质分析

远缘杂交能够有效拓宽物种的遗传背景,产生丰富的遗传变异。前期研究中利用体细胞融合技术获得了甘蓝型油菜扬油6号(Y6)与白芥的属间杂种,将杂种与Y6连续回交和自交得到了一系列稳定遗传的渐渗系株系。本研究以62个渐渗系株系为材料,对这些株系进行14个农艺性状的考察,并通过相关性分析、主成分分析、回归分析和聚类分析等方法,探究甘蓝型油菜单株产量与农艺性状之间的关系及影响单株产量的主要因素。结果显示,甘蓝型油菜-白芥渐渗系株系的农艺性状存在较大差异;单株产量与全株角果数、有效分枝数和每角粒数等性状呈极显著正相关,而与分枝点高度呈极显著负相关。主成分分析的结果表明,4个主成分可以概括14个农艺性状的大部分信息,这些主成分主要与角果数目、株高、角果长度和千粒重等性状指标相关。回归分析结果表明,千粒重、每角粒数、二次有效分枝数、株高和全株角果数对单株产量具有重要影响。综合各项指标,筛选出一些具有优异农艺性状的材料,如L8等株系角果数目明显增多;L3、L7等株系分枝数目明显增多;L42、L49等株系千粒重明显增加;L3、L8等株系单株产量明显提高。利用近红外光谱仪分析渐渗系材料种子品质性状,发现硫代葡萄糖甘、芥酸、亚麻酸等品质性状存在较大变异,可用于选育具有优良品质性状的材料。本研究表明远缘杂交对于甘蓝型油菜种质资源创新、提高油菜产量提供了一条有效途径,研究结果为利用这些种质资源进行育种实践提供了理论依据。     

甘蓝型油菜若干农艺性状与单株产量的关系分析

以38个甘蓝型油菜品种为材料,对单株产量、有效分枝部位高度、主轴花序长度等11个农艺性状进行了方差分析、通径分析和聚类分析．结果显示:所有调查性状在品种间存在显著的差异;主花序长度、主序有效角果数与单株产量都有显著的遗传相关性,两者都通过有效分枝部位高度对单株产量产生较大的正向间接作用;有效分枝部位高度对单株产量的影响也较显著,高产品种具有相对较高的有效分枝部位高度;总角果数对单株产量的直接遗传通径系数虽小,但它具有最大的直接表型通径系数,它通过主序有效角果数和有效分枝数对单株产量产生了两个较大的间接作用;要获得3130kg/hm~2的产量,重点应具备果多、枝多的特征,总角果数不少于657个,有效分枝数不少于18个．     

江苏省直立穗型粳稻品种主要农艺性状和品质性状分析

通过对江苏省淮北稻区种植的主要粳稻品种品质状况和近十年来育成的直立穗型粳稻品种(系)主要品质和农艺性状的分析,发现前期育成直立穗型粳稻品种相时半直立穗型粳稻品种加工品质低,垩白率高和垩白度大,蛋白质含量高;而近期育成直立穗型粳稻品种在上述品质指标上有了较大改进,食味品质也有了显著提高.在主要农艺性状中,近期育成品种呈现每穗总粒数上升、穗长变长、着粒密度下降趋势,产量水平的提高与每穗粒数的增加有着紧密相关.     

南疆棉区棉花品种的特性演变与育种潜力研究

南疆棉区经过5次大的品种更换,高产品种的选育起了非常重要的作用,新育成的品种比早期育成的品种产量以每年12.1kg/hm2的速度增长,品种改良对产量的贡献率为43.9%。衣分、单株结铃数和单铃重的总的演变趋势是增加的,农艺性状方面株高降底,株宽增加,自育品种的现蕾量较低,脱落率较高,南疆棉花品种的综合品质变化不大,特别是棉花生产品质未发生根本性变化。南疆棉花品种在单株结铃数、衣分、增加现蕾数、降低花蕾脱落、株宽、果枝始节、高光合速率品种的选育以及纤维比强度等方面具备较大的选择潜力。     

西藏与周边地区芥菜型油菜农艺性状比较研究

运用典范相关分析方法,对西藏及周边地区芥菜型油菜的产量性状、主茎性状、分枝性状、角果性状等4组性状间的典范相关关系进行了比较研究.结果表明:(1)所研究的18个性状中,西藏芥菜型油菜的平均数为周边地区芥菜型油菜的1.88倍,总体变异系数比周边省份芥菜型油菜高10.22％;(2)西藏芥菜型油菜单株产量主要取决于每株角果数和千粒重,而周边省份芥菜型油菜单株产量主要取决于每株有效角果数,中国周边国家芥菜型油菜单株产量主要取决于每株有效角果数和千粒重;(3)影响西藏芥菜型油菜产量性状最重要的因素是角果性状,其次是分枝性状和主茎性状,而影响周边省份和中国周边国家芥菜型油菜产量性状最重要的因素则是主茎性状,其次是分枝性状和角果性状.     

甘蓝型油菜生殖生长期叶片和角果光合与产量关系的研究

以11个不同适生区甘蓝型油菜品种为材料,研究了油菜生殖生长期植株叶片和角果的光合气体交换参数、光合色素含量、光合关键酶蛋白含量、主要农艺性状及其与产量的关系,探讨影响叶片(角果)光合效率及单株籽粒产量的主要因子,为油菜高产高光效品种的系统评价提供理论依据。结果显示:(1)油菜植株叶片与角果的净光合速率间相关性较小,但叶片净光合速率远大于角果。(2)叶片净光合速率与其叶绿素a+b含量及气孔导度呈不显著的正相关关系(相关系数较大),与其光合关键酶PEPC、RuBisCO蛋白含量相关系数较小或呈不显著负相关;角果(皮)净光合速率与其叶绿素a、b含量、类胡萝卜素含量及气孔导度相关性较强;光合色素含量是影响叶片、角果净光合速率的第一主因子。(3)单株叶面积、角果数及角果表面积与籽粒产量显著正相关关系,是影响籽粒产量的第一主因子;叶片净光合速率和角粒数是影响籽粒产量的第二主因子;单株生物学产量与叶面积呈显著正相关关系,角果表面积、叶面积及叶片净光合速率是影响生物学产量的第一、二主要因子。研究表明,油菜高产高光效品种的综合评价指标应首选单株角果数、叶片面积,其次选择叶片净光合速率、叶片和角果皮的叶绿素含量以及角粒数。     

适宜河北省旱寒区的冬油菜品种的筛选

筛选适宜河北省低平原地区种植的油菜品种,同时实现生态效益和经济效益,为相似气候区油菜品种的种植选择及种植结构的调整提供理论依据。以16个油菜品种为材料,对品种间农艺性状的变化进行方差分析、相关性分析和聚类分析。各品种间分枝部位存在差异,变异系数为61.82%,品种JR5分枝部位最低,14T×38最高;其次差异较为明显的是产量和二次分枝数,变异系数分别为26.69%和24.89%,14T×38产量最高,20SY-13最低。二次分枝数最大和最小的品种分别为20SY-13和天油142。油菜产量与一次分枝数和主花序角果数呈极显著正相关(P<0.01),株高与分枝部位、主花序长度和主花序角果数呈显著正相关关系,一次分枝数与主花序角果数呈显著正相关(P<0.05),二次分枝数与主花序角果数呈极显著负相关。当欧式距离为5时,16个油菜品种可分为五大类。选择株高较高、一次分枝数和主花序角果数较多、二次分枝数较少且可以在当地正常越冬的油菜品种进行种植,可以获得较高水平产量;20SY-13在当地秋季种植应注意安全越冬。     

不同施磷量对春油菜产量和土壤磷素平衡的影响

青海省东部春油菜主产区的土壤速效磷含量高、磷肥施用量大、磷肥利用率低。研究不同施磷量对春油菜的生长、磷素吸收和利用、土壤磷素平衡的影响,可为该地区春油菜田养分高效管理提供科学依据,对保障青藏高原农业可持续发展具有重要意义。本研究于2017和2018年在青海省互助县开展了田间试验,设置0、30、60、90、120 kg P₂O₅·hm^-2 5个磷肥施用量,测定了不同处理春油菜的产量、磷素吸收与利用、籽粒含油率等。结果表明: 2017年施磷量60 kg·hm^-2处理的油菜籽粒产量、成熟期地上部磷素累积量和产油量均显著高于不施磷处理,但施磷量超过60 kg·hm^-2后,籽粒产量和产油量不再增加;2018年施磷量对春油菜籽粒产量、成熟期地上部磷素累积量和产油量均无显著影响。两年度的磷肥表观利用率均很低,平均为6.7%。施用磷肥条件下土壤均有不同程度的磷素盈余,施磷量低于60 kg·hm^-2时盈余量较低。综合考虑春油菜产量、产油量、磷肥表观利用率和土壤磷素表观平衡,在青海省东部春油菜区,推荐施磷量为60 kg·hm^-2。     

油菜油脂研究进展

油菜（Brassica napus）是世界范围内重要的油料作物,是植物油脂的第三大来源,其种植面积和总产量在油料作物中占有相当大的比例。我国油菜品种油脂含量普遍较国外低2—5个百分点,而油脂含量每增加1个百分点对产油量提高的贡献,相当于菜籽产量提高2．5个百分点。因此提高油菜油脂含量是解决油菜生产效益低的重要途径之一。本文综述了油菜油脂研究的状况,包括油脂积累的遗传学基础、油脂合成途径和调控、油脂含量的QTL定位及油脂含量与品质性状的遗传相关性,同时展望了油菜油脂研究前景,以期为油菜油脂含量的品种改良提供科学指导。     

油菜油脂研究进展

油菜(Brassica napus)是世界范围内重要的油料作物, 是植物油脂的第三大来源, 其种植面积和总产量在油料作物中占有相当大的比例。我国油菜品种油脂含量普遍较国外低2-5个百分点, 而油脂含量每增加1个百分点对产油量提高的贡献, 相当于菜籽产量提高2.5个百分点。因此提高油菜油脂含量是解决油菜生产效益低的重要途径之一。本文综述了油菜油脂研究的状况, 包括油脂积累的遗传学基础、油脂合成途径和调控、油脂含量的QTL定位及油脂含量与品质性状的遗传相关性, 同时展望了油菜油脂研究前景, 以期为油菜油脂含量的品种改良提供科学指导。     

Functional disruption of the pentatricopeptide protein SLG1 affects mitochondrial RNA editing, plant development, and responses to abiotic stresses in Arabidopsis

Seed oil content is an important agronomic trait in rapeseed. However, our understanding of the regulatory processes controlling oil accumulation is still limited. Using two rapeseed lines (zy036 and 51070) with contrasting oil content, we found that maternal genotype greatly affects seed oil content. Genetic and physiological evidence indicated that difference in the local and tissue-specific photosynthetic activity in the silique wall (a maternal tissue) was responsible for the different seed oil contents. This effect was mimicked by in planta manipulation of silique wall photosynthesis. Furthermore, the starch content and expression of the important lipid synthesis regulatory gene WRINKLED1 in developing seeds were linked with silique wall photosynthetic activity. 454 pyrosequencing was performed to explore the possible molecular mechanism for the difference in silique wall photosynthesis between zy036 and 51070. Interestingly, the results suggested that photosynthesis-related genes were over-represented in both total silique wall expressed genes and genes that were differentially expressed between genotypes. A potential regulatory mechanism for elevated photosynthesis in the zy036 silique wall is proposed on the basis of knowledge from Arabidopsis. Differentially expressed ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco)-related genes were used for further investigations. Oil content correlated closely with BnRBCS1A expression levels and Rubisco activities in the silique wall, but not in the leaf. Taken together, our results highlight an important role of silique wall photosynthesis in the regulation of seed oil content in terms of maternal effects.     

Effects of Heat Stress during Seed Filling Stage on <i>Brassica napus</i> Seed Oil Accumulation and Chlorophyll Fluorescence Characteristics

As global temperature rise, the threat of heat stress to rapeseed production is becoming more obvious. Exploring the response characteristics of two important biological pathways, oil accumulation and photosynthesis, to heat stress during B. napus seed filling is helpful in the genetic improvement of heat-tolerant rapeseed. The effects of heat stress on seed oil accumulation and chlorophyll fluorescence characteristics of 29 B. napus germplasms with different oil content and environmental sensitivity, including 6 rapeseed varieties which exhibited environment-sensitive/insensitive and with high, medium or low oil content, were tested by whole plant heat stress or the in vitro silique culture system. Both assay exhibited similar trend on oil content of the rapeseed germplasms. The heat effect on the chlorophyll fluorescence kinetic parameters F_v/F_m, ETR and Y(II) were also consistent. Heat stress significantly decreased oil content, although there was abundant genetic variation on heat tolerance among the genotypes. Correlation analysis showed that the decrease rate of F_v/F_m of silique heat-stressed B. napus developing seed was positive correlative to the decrease rate of mature seed oil content of the whole plant heat-stressed rapeseed (R = 0.9214, P-value < 0.01). Overall, the results indicated that heat stress inhibited oil accumulation and photosynthesis in B. napus developing seed. The decrease rate of chlorophyll fluorescence parameter F_v/F_m of heat-stressed developing seed could be used as the index of heat tolerant rapeseed identification. Further, two heat insensitive rapeseed varieties with high oil content were identified.     

Precise editing of CLAVATA genes in Brassica napus L. regulates multilocular silique development

Multilocular silique is a desirable agricultural trait with great potential for the development of high‐yield varieties of Brassica. To date, no spontaneous or induced multilocular mutants have been reported in Brassica napus, which likely reflects its allotetraploid nature and the extremely low probability of the simultaneous random mutagenesis of multiple gene copies with functional redundancy. Here, we present evidence for the efficient knockout of rapeseed homologues of CLAVATA3 (CLV3) for a secreted peptide and its related receptors CLV1 and CLV2 in the CLV signalling pathway using the CRISPR/Cas9 system and achieved stable transmission of the mutations across three generations. Each BnCLV gene has two copies located in two subgenomes. The multilocular phenotype can be recovered only in knockout mutations of both copies of each BnCLV gene, illustrating that the simultaneous alteration of multiple gene copies by CRISPR/Cas9 mutagenesis has great potential in generating agronomically important mutations in rapeseed. The mutagenesis efficiency varied widely from 0% to 48.65% in T₀ with different single‐guide RNAs (sgRNAs), indicating that the appropriate selection of the sgRNA is important for effectively generating indels in rapeseed. The double mutation of BnCLV3 produced more leaves and multilocular siliques with a significantly higher number of seeds per silique and a higher seed weight than the wild‐type and single mutant plants, potentially contributing to increased seed production. We also assessed the efficiency of the horizontal transfer of Cas9/gRNA cassettes by pollination. Our findings reveal the potential for plant breeding strategies to improve yield traits in currently cultivated rapeseed varieties.     

Important photosynthetic contribution of silique wall to seed yield-related traits in <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis>

In plants, green non-foliar organs are able to perform photosynthesis just as leaves do, and the seed-enclosing pod acts as an essential photosynthetic organ in legume and Brassica species. To date, the contribution of pod photosynthesis to seed yield and related components still remains largely unexplored, and in Arabidopsis thaliana, the photosynthetic activity of the silique (pod) is unknown. In this study, an Arabidopsis glk1/glk2 mutant defective in both leaf and silique photosynthesis was used to create tissue-specific functional complementation lines. These lines were used to analyze the contribution of silique wall photosynthesis to seed yield and related traits, and to permit the comparison of this contribution with that of leaf photosynthesis. Our results showed that, together with leaves, the photosynthetic assimilation of the silique wall greatly contributed to total seed yield per plant. As for individual components of yield traits, leaf photosynthesis alone contributed to the seed number per silique and silique length, while silique wall photosynthesis alone contributed to thousand-seed weight. In addition, enhancing the photosynthetic capacity of the silique wall by overexpressing the photosynthesis-related RCA gene in this tissue resulted in significantly increased seed weight and oil content in the wild-type (WT) background. These results reveal that silique wall photosynthesis plays an important role in seed-related traits, and that enhancing silique photosynthesis in WT plants can further improve seed yield-related traits and oil production. This finding may have significant implications for improving the seed yield and oil production of oilseed crops and other species with pod-like organs.     

甘蓝型油菜遗传图谱的构建及单株产量构成因素的QTL分析

采用常规品系04-1139与高产多角果品系05-1054构建的F2代群体为作图群体, 运用SSR(Simple sequence repeat)和SRAP(Sequence-related amplified polymorphism)构建分子标记遗传图谱并对甘蓝型油菜单株产量构成因素进行QTL分析。遗传图谱包含200个分子标记, 分布于19个连锁群上, 总长度1 700.23 cM, 标记间的平均距离8.50 cM。采用复合区间作图法(Composite interval mapping, CIM)对单株产量构成因素(单株有效角果数、每果粒数和千粒重)进行QTL分析, 共检测到12个QTL: 其中单株有效角果数4个QTL, 分别解释表型变异为35.64%、12.96%、28.71%和34.02%; 每果粒数获得5个QTL, 分别解释表型变异为8.41%、7.87%、24.37%、8.57%和14.31%; 千粒重获得３个QTL, 分别解释表型变异为2.33%、1.81%和1.86%。结果表明: 同一性状的等位基因增效作用可以同时来自高值亲本和低值亲本; 文章中与主效QTL连锁的标记可用于油菜产量性状的分子标记辅助选择和聚合育种。     

Enhanced seed oil production in canola by conditional expression of Brassica napus LEAFY COTYLEDON1 and LEC1-LIKE in developing seeds

The seed oil content in oilseed crops is a major selection trait to breeders. In Arabidopsis (Arabidopsis thaliana), LEAFY COTYLEDON1 (LEC1) and LEC1-LIKE (L1L) are key regulators of fatty acid biosynthesis. Overexpression of AtLEC1 and its orthologs in canola (Brassica napus), BnLEC1 and BnL1L, causes an increased fatty acid level in transgenic Arabidopsis plants, which, however, also show severe developmental abnormalities. Here, we use truncated napin A promoters, which retain the seed-specific expression pattern but with a reduced expression level, to drive the expression of BnLEC1 and BnL1L in transgenic canola. Conditional expression of BnLEC1 and BnL1L increases the seed oil content by 2% to 20% and has no detrimental effects on major agronomic traits. In the transgenic canola, expression of a subset of genes involved in fatty acid biosynthesis and glycolysis is up-regulated in developing seeds. Moreover, the BnLEC1 transgene enhances the expression of several genes involved in Suc synthesis and transport in developing seeds and the silique wall. Consistently, the accumulation of Suc and Fru is increased in developing seeds of the transgenic rapeseed, suggesting the increased carbon flux to fatty acid biosynthesis. These results demonstrate that BnLEC1 and BnL1L are reliable targets for genetic improvement of rapeseed in seed oil production.     

A CACTA‐like transposable element in the upstream region of BnaA9.CYP78A9 acts as an enhancer to increase silique length and seed weight in rapeseed

Rapeseed (Brassica napus L.) is a model plant for polyploid crop research and the second‐leading source of vegetable oil worldwide. Silique length (SL) and seed weight are two important yield‐influencing traits in rapeseed. Using map‐based cloning, we isolated qSLWA9, which encodes a P450 monooxygenase (BnaA9.CYP78A9) and functions as a positive regulator of SL. The expression level of BnaA9.CYP78A9 in silique valves of the long‐silique variety is much higher than that in the regular‐silique variety, which results in elongated cells and a prolonged phase of silique elongation. Plants of the long‐silique variety and transgenic plants with high expression of BnaA9.CYP78A9 had a higher concentration of auxin in the developing silique; this induced a number of auxin‐related genes but no genes in well‐known auxin biosynthesis pathways, suggesting that BnaA9.CYP78A9 may influence auxin concentration by affecting auxin metabolism or an unknown auxin biosynthesis pathway. A 3.7‐kb CACTA‐like transposable element (TE) inserted in the 3.9‐kb upstream regulatory sequence of BnaA9.CYP78A9 elevates the expression level, suggesting that the CACTA‐like TE acts as an enhancer to stimulate high gene expression and silique elongation. Marker and sequence analysis revealed that the TE in B. napus had recently been introgressed from Brassica rapa by interspecific hybridization. The insertion of the TE is consistently associated with long siliques and large seeds in both B. napus and B. rapa collections. However, the frequency of the CACTA‐like TE in rapeseed varieties is still very low, suggesting that this allele has not been widely used in rapeseed breeding programs and would be invaluable for yield improvement in rapeseed breeding.     

An analysis of association of components of yield and oil in safflower (Carthamus tinctorius L.)

Summary Inter-relationships of various component characters with yield and oil content were analysed using 215 entries of safflower from India and U.S.A. Correlation of capsule number per plant and capsule weight with yield per plant was pronounced and they showed large direct effects on yield. All other components influenced seed yield mainly through these two components. Seed size had little effect on yield while seed number exerted a positive influence. The proportion of hull expressed as per cent of the whole seed revealed a highly significant and inverse relationship with oil content and was mainly responsible for the observed variability in oil content in the material. Although negative association was indicated between seed size and oil content, it was observed to be due to the indirect effect of hull content and not due to direct effect of seed size. Interestingly, yield per plant and its major components, number of capsules and capsule weight, revealed a negligible relationship with oil content. Both direct as well as indirect effects of hull percent and yield per plant were responsible for the favourable effect of seed number on oil content. The correlation of plant height, days to first flowering and total crop growth period with yield and oil content was either negligible or low, offering scope for developing early maturing and dwarf varieties with high yield and oil content. Spine index showed a non-significant association with yield and oil content. Capsule number, capsule weight and hull per cent were observed to be the most important components in breeding for higher yield and oil content.