福建山区生境黄花倒水莲生殖构件表型可塑性及变化规律

为了解黄花倒水莲生殖构件表型可塑性及变化规律,在福建山区竹林群落内,采用大样本随机取样,对黄花倒水莲种群的生殖构件进行了表型可塑性的研究。结果表明,在籽实完熟期,黄花倒水莲的单个生殖植株的生物量(58.67±35.77) g;豆荚生物量及豆荚数分别为(6.64±4.93) g、(35.6±30.50)个;种子生物量与种子数分别为(2.61±2.19) g、(61.97±54.15)粒;生殖分配Ⅰ与生殖分配Ⅱ分别为10.55%±3.39%、3.93%±1.62%;各生殖构件表型观测最大值与最小值比值为4.23~39.5。豆荚生物量及豆荚数、种子生物量与种子数与总生物量间呈极显著性的线性正相关关系;豆荚数、种子数、生殖分配Ⅰ与生殖分配Ⅱ与其他组分生物量分配呈极显著性幂函数负相关关系。黄花倒水莲种群生殖植株同时具有同速生长和异速生长2种不同增减过程的表型可塑性调节。     

松嫩平原蒺藜草(Cenchrus incertus)种群构件生物量分配

通过对松嫩平原蒺藜草(Cenchrus incertus)单优群落植株的取样调查,对其构件的生物量结构、生物量分配进行了定量分析。结果表明:蒺藜草种群籽粒成熟期各构件生物量大小为叶茎花序根,其变异系数分别为167.51%、173.79%、207.37%和125.79%,具有较大的表型可塑性;蒺藜草各构件生物量分配比例大小关系表现为叶茎根花序。蒺藜草植株大小随着根、茎、叶及花生物量的增加呈直线函数形式增加,花生物量分配与总生物量呈显著的正相关性,其余构件生物量分配均与总生物量呈负相关性。     

国外微型月季品种资源主要表型分析及综合评价

为了提高微型月季种质资源的利用率,从12个数量性状和8个质量性状对国外引进的微型月季主栽种质资源,进行了表型性状遗传多样性研究。结果表明,微型月季表型性状的种间变异系数为花直径的变异系数(20.61%)最大,侧叶宽变异系数(1.68%)最小;种内变异系数为柄叶数变异系数(15.14%)最大,花瓣长变异系数(4.95%)最小;数量性状的Shannon-weaver多样性信息指数H'在0.852~2.777之间,平均值为1.960。基于20个表型性状数据,将种质资源分为花型、叶型、叶刺、花色等5个不同类型。数量性状的前7个主成分累计方差贡献率达到91.75%,反映的信息与聚类分析和相关分析结果基本一致。花色、花型等经济性状表型性状指标的影响较大,结合相关性分析和主成分分析,20个数量性状可简化为花型、叶型、花色、叶刺等5个主要性状。以上结果为微型月季的资源评价和品种选育提供了重要的物质基础和理论依据。     

窄叶鲜卑花种子萌发特性的研究

对窄叶鲜卑花种子的形态特征及温度、光照对种子萌发特性的影响进行了研究。结果表明:窄叶鲜卑花种子的千粒重约为0.115g,种子长(0.255±0.02)cm、宽(0.042±0.01)cm、厚(0.014±0.01)cm。在15℃的恒温条件下开始萌发,在25~30℃条件下发芽率达73.10%~82.67%,为最适发芽温度;在变温条件下,25℃/10℃为最适发芽温度,发芽率达70.87%;在30℃光照24h的条件下,窄叶鲜卑花种子发芽率高达83.33%,且发芽势、发芽指数、种子活力与其他处理相比均达到最高值,由此可知,在温度、水分适宜的条件下,增加光照有利于种子发芽率的提高。     

施磷量对黑木相思苗木生长的影响

为探究黒木相思苗木生长变化对磷肥的反映机制,本研究对1a生黑木相思(Acacia melanoxylon)苗木采用随机区组设计,设置了7个不同施肥量处理(0、50、75、100、125、150、200 mg P/株),测定并分析其苗高、地径、生物量及根系形态指标。结果表明：不同施磷量对苗木高生长、地径、生物量(地上部分、地下部分生物量)以及根系的生长都起促进作用,随时间和施磷量的增加,黑木相思根长、根平均直径、根表面积、根体积、苗高、地径、生物量总体表现均有所增加,总量为100 mg/株的等量施磷量对苗木生长促进作用效果最佳,试验结束时(即施肥第12 wk),该处理的根长、根表面积、根平均直径、根体积、苗高、地径、生物量(地上、地下部分)分别为417.09 cm、35.16 cm2、0.46cm、0.48cm3、36.2mm、2.30mm、1.236g(地上部分)、0.227g(地下部分),其中根长、根表面积、根平均直径、根体积分别比对照增加了81.2%、110.7%、61.2%和127.1%。     

浙江主栽盆栽百合种质资源表型性状遗传多样性分析

对浙江省主栽的18份盆栽百合种质资源的21个表型性状进行了变异水平评价、相关性分析和遗传多样性分析。结果表明:盆栽百合品种间具有丰富的表型多样性,在品种间均表现出极显著差异。各个性状的表型分化系数VST在96.50%～99.17%之间,平均值为97.95%,群体间平均表型变异约占总变异的97%,表明品种间的变异是盆栽百合品种表型性状变异的主要来源,品种内的变异对百合品种表型性状变异影响不大。各表型性状的平均变异系数(CV)为9.14%,性状离散程度低;不同品种之间性状多样性指数均有不同程度的变异,数量性状中指数最高为花序长(3.689),质量性状中指数最高为花瓣主色(1.765)。Pearson相关性分析发现,盆栽百合的整株花型与营养生长存在显著相关性;相关性状正相关明显大于负相关。表型聚类结果表明,表型性状聚类分析结果与相关性分析一致,18份种质资源被划分为5个居群,基本按花朵表现型而聚类划分。本研究确定表型数据是百合较为合理的评判指标,为盆栽百合育种资源研究提供参考和依据。     

中国板栗北方种群表型变异频率研究

研究了中国板栗北方产区5个地理种群种子及叶片特征的表型分化、表型性状值(数量性状)的频率分布及表型频率多样性。结果表明,板栗种群间的方差分量占总变异的10.97%,种群内的占41.57%,7个性状种群间的表型分化系数变幅在11.85%~28.34%。板栗7个性状种群间的表型分化系数平均为24.26%,表明种群内变异是板栗表型变异的主要来源,种群内品种间的多样性大于种群间的多样性。板栗7个性状频率分布基本符合正态分布,但偏度和削度各自不同,众数的位置及所在组的频率也存在一定差异。表型多样度、Shannon信息指数均可用于表型多样性的评价。     

甘蓝型杂交油菜主花序长度与植株性状的相关分析

为研究甘蓝型杂交油菜主花序长度与植株性状间的相关关系,以649 个甘蓝型杂交油菜组合进行田间试验、室内考种及相关分析。结果表明：甘蓝型杂交油菜主花序长度平均为45.67 cm,变幅范围为(28.00~66.65 cm),且长主花序材料很少;主花序长度的变异系数较小,遗传力较高,不易受坏境条件的影响,适合早代选择;主花序长度与株高(r=0.8262)、主花序角果数(r=0.7804)、单株角果数(r=0.7466)、一次分枝数(r=0.4680)、主花序角果长度(r=0.3164)、角粒数(r=0.2322)均呈极显著正相关,主花序长度与有效分枝位及千粒重呈不显著正相关,单株产量与单株角果数、主花序角果数、主花序长度、株高、一次分枝数均呈极显著正相关,主花序角果长度与角粒数、千粒重呈极显著正相关;利用相关性分析可知,选育长主花序的材料,能有效提高株高、主花序角果数、单株角果数、一次分枝数、主花序角果长度、角粒数,从而达到提高油菜产量的目的。结合当前直播或机播油菜高密植生产要求,应当选育主序长、主花 序角果数多、角果较长、单株产量高的材料。     

滇西北野生牡丹天然居群的表型多样性

为揭示滇西北天然牡丹居群的表型变异程度和变异规律,利用12 个形态指标对18 个滇西北牡丹(Paeonia delavayi)的天然居群进行表型多样性研究。结果表明：滇西北牡丹表型性状在居群间存在广泛的变异,12 个性状居群间的变异系数为16.65%~107.78%,种群间的平均变异系数为38.44%。在研究的18 个居群中,宁蒗拉伯乡居群的变异最小,变异系数为25.02%;其次是玉龙县大平坝居群,变异系数为26.68%;以丽鸣线路旁居群的变异为最大,变异系数为50.86%。滇西北牡丹变型性状在居群间和居群内存在着丰富的表型多样性,12 个表型性状的平均表型分化系数为98.51%,居群间的变异(48.87%)大于居群内的变异(0.59%),表明居群间的变异是表型变异的主要来源。滇西北牡丹表型性状与地理因子的典型相关分析表明,坡度能正向依次解释单荚荚长(y11)、果柄长(y8)、叶柄长(y4)和单荚总数(y10),负向依次解释单荚荚宽(y12)、荚果数(y9)和株高(y1);聚类分析结果说明滇西北牡丹居群间表型性状变异是不连续的。     

民勤沙区典型一年生植物沙米构件特征研究

[目的]为掌握沙区一年生植物个体形态和构件特征,[方法]通过样地调查、室内测定和统计分析,对民勤沙区自然分布的典型一年生植物沙米个体形态特征及构件特征进行了观测研究,并分析了构件生物量与植株高度的关系。[结果]结果表明,沙米个体形态指标值变异系数大,尤其根长和侧根数变异系数大于50 %,反映出沙米对生长环境的良好适应性和调节能力；沙米个体生物量干重介于24.55 g～138.09 g之间,各构件生物量干重分配值的大小顺序是果穗(36.51±26.07 g)>枝条(31.00±20.26 g)>叶(24.09±12.97 g)>根(6.63±3.75 g),沙米生长中将生物量尽可能多地分配到繁殖构件中；沙米单株的含水率70.89±1.61 %,构件的含水率在64.91 %～74.97 %之间,且不同构件的含水率存在差异；沙米各构件生物量分配随植株高度的增加以幂函数关系增加,是沙米个体生长发育能力调节策略的表现。[结论]沙米对生长环境的适应性选择差异造成个体形态特征的差异,生长中将尽可能多地把生物量分配到繁殖构件中以确保种的延续,可以用株高通过模拟模型来衡量出各构件的生物量分配值,为荒漠生态系统中一年生植物的研究提供支撑依据。     

Root system plasticity to drought influences grain yield in bread wheat

Crop productivity in semiarid regions is mainly limited by water availability. Root characteristics and plasticity to drought may reduce the negative impact of drought on crop yield. A set of near-isogenic wheat-rye translocation lines was used to test the hypothesis that root system plasticity to drought influences grain yield in wheat. Bread wheat Pavon 76 and 1RS translocation lines, namely Pavon 1RS.1AL, Pavon 1RS.1BL, and Pavon 1RS.1DL were evaluated for root allocation and plasticity in sand-tube experiments under well-watered and droughted conditions across 2 years using factorial treatments in a randomized complete block design with four replicates. The 1RS translocation lines had greater root biomass per plant ranging from 7.37 to 8.6 compared to 5.81 g for Pavon 76. Only Pavon 76 showed a positive response to drought by producing more shallow roots (roots developed between 0 and 30 cm) and deep roots (roots developed below 30 cm) in droughted conditions than in well-watered conditions. Thus at drought intensity of 19% (measured as overall reduction in grain yield), grain yield in Pavon 76 was reduced only by 11% compared to the other genotypes with yield reductions ranging from 18 to 24%. However, at drought intensity of 36%, grain yield in Pavon 76 showed maximum reduction indicating that greater root production under drought is advantageous only when plant-available water is enough to support grain production. Grain yield was positively correlated with shallow and deep root weight and root biomass under terminal drought. Correlation coefficients between root system components (shallow and deep root weight and root biomass) and phenological periods were not significant. Our study indicated that genes influencing adaptive phenotypic plasticity of the root system to drought in Pavon 76 are located on chromosome 1BS.     

高寒矮嵩草草甸4种主要植物补偿生长变化与耐牧性比较研究

为了探讨高寒矮嵩草草甸4种主要植物的补偿生长机制和耐牧性差异,通过裂区区组设计的方法进行刈割（留茬1 cm、3 cm及不刈割对照）、施肥（施尿素和磷酸二胺、不施）和浇水（浇、不浇）控制实验,调查研究了垂穗披碱草(Elymus nutans)、异针茅(Stipa aliena)、矮嵩草(Kobresia humilis)和粗喙薹草(Carex scabrirostris)分株密度、株高和分株地上生物量及其相对生长率的变化。研究结果表明：2种禾本科植物垂穗披碱草和异针茅的补偿高度和地上补偿生物量对刈割的响应更加敏感;刈割后异针茅、矮嵩草和粗喙薹草的分株密度发生超补偿,4种植物的株高相对生长率都显著增加,地上生物量相对生长率在种间存在较大差异。4种植物的耐牧性大小顺序为矮嵩草>粗喙薹草>垂穗披碱草>异针茅。施肥能显著提高4种植物的补偿高度、地上补偿生物量、株高相对生长率和耐牧性,说明在具有明显的土壤养分限制作用的高寒草甸群落中,植物的耐牧性依赖于土壤速效养分的可获得性。     

齐齐哈尔市水稻田杂草群落变化趋势的分析

为明确齐齐哈尔市水稻田杂草种类、群落组成及危害状况,为高效防治水稻田杂草提供依据。采用倒置“Ｗ”形9点取样方法,进行定点系统观测与田间普查,田间调查方法为定点计数法与随机目测法,田间调查主要为杂草类别、群落组成结构和危害级别程度。结果表明：异型莎草、芦苇、稻稗、针蔺等杂草在稻田杂草群落出现频率在20年间明显下降,野慈姑、雨久花、鸭舌草、泽泻、稻李氏禾、葡茎剪股颖在杂草种群中的出现频率明显上升,杂草的危害程度随着其出现频率的变化而变化,造成很大危害。水稻田杂草群落模式由“禾本科杂草+莎草科杂草+阔叶类杂草”演替为“阔叶类杂草+禾本科杂草+莎草科杂草”,其中难治的恶性杂草种类增加且危害严重。     

不同浓度NaCl胁迫对红桤木幼苗生长及部分生理指标的影响

在盆栽控盐的条件下,研究红桤木在0g/L,2 g/L,4 g/L和6 g/L的盐胁迫下生长量、生物量、叶绿素、POD、SOD等指标的动态变化过程。实验结果表明：随着盐胁迫程度的加重,红桤木的株高、生物量、根冠比、叶绿素含量都显著减少;2 g/L的盐胁迫对红桤木的影响与对照相比差异不显著,茎和叶生物量略高于对照,叶绿素含量在胁迫前期高于对照。在胁迫前期和中期POD、SOD活性随着胁迫的加重而上升;在盐处理后期,6 g/L的盐胁迫下的POD活性急速下降,2 g/L的盐胁迫下SOD和POD活性开始上升。     

南方红豆杉人工林培育模式对生物量及其分配格局影响

本研究通过了解南方红豆杉生长、干形变化、生物量积累与分配格局的培育模式响应机制,为南方红豆杉林下栽培体系提供理论基础,在福建明溪对林下套种与纯林培育模式12年生南方红豆杉的生长、干形、生物量积累与分配进行调查。结果表明,培育模式对南方红豆杉树高、胸径、冠幅、单株材积、高径比和生物量有显著性影响,林下套种显著促进南方红豆杉生长,改良干形品质,利于南方红豆杉构件生物量及总生物量积累;不同培育模式中南方红豆杉生物量分配比大小顺序均为干＞枝＞叶;培育模式对南方红豆杉生物量分配比与构件生物量比有着显著性影响,林下套种南方红豆杉增加枝、叶、干等地上生物量分配比,降低根系生物量分配比;林下套种的生物量更趋向地上部分、干和叶的分配;南方红豆杉人工林林下套种较纯林培育模式促进生物量高效积累与有效分配。     

Variance components and heritability of traits related to root: shoot biomass allocation and drought tolerance in wheat

Enhanced root growth in plants is fundamental to improve soil water exploration and drought tolerance. Understanding of the variance components and heritability of root biomass allocation is key to design suitable breeding strategies and to enhance the response to selection. This study aimed to determine variance components and heritability of biomass allocation and related traits in 99 genotypes of wheat (Triticum aestivum L.) and one triticale (X. Triticosecale Wittmack) under drought-stressed and non-stressed conditions in the field and greenhouse using a 10?×?10 alpha lattice design. Days to heading (DTH), days to maturity (DTM), number of tillers (NPT), plant height (PH), spike length (SL), shoot and root biomass (SB, RB), root to shoot ratio (RS), thousand kernel weight (TKW) and yield (GY) were recorded. Analyses of variance, variance components, heritability and genetic correlations were computed. Significant (p?<?0.05) genetic and environmental variation were observed for all the traits except for spike length. Drought stress decreased heritability of RS from 47 to 28% and GY from 55 to 17%. The correlations between RS with PH, NPT, SL, SB and GY were weaker under drought-stress (r?≤???0.50; p?<?0.05) compared to non-stressed conditions, suggesting that lower root biomass allocation under drought stress compromises wheat productivity. The negative association between GY and RS (r?=???0.41 and ??0.33; p?<?0.05), low heritability (<?42%) and high environmental variance (>?70%) for RS observed in this population constitute several bottlenecks for improving yield and root mass simultaneously. However, indirect selection for DTH, PH, RB, and TKW, could help optimize RS and simultaneously improve drought tolerance and yield under drought-stressed conditions.     

Selection of wheat genotypes for biomass allocation to improve drought tolerance and carbon sequestration into soils

The biomass allocation pattern of plants to shoots and roots is a key in the cycle of elements such as carbon, water and nutrients with, for instance, the greatest allocations to roots fostering the transfer of atmospheric carbon to soils through photosynthesis. Several studies have investigated the root to shoot ratio (R:S) biomass of existing crops but variation within a crop species constitutes an important information gap for selecting genotypes aiming for increasing soil carbon stocks for climate change mitigation and food security. The objectives of this study were to evaluate agronomic performance and quantify biomass production and allocation between roots and shoots, in response to different soil water levels to select promising genotypes for breeding. Field and greenhouse experiments were carried out using 100 genotypes including wheat and Triticale under drought‐stressed and non‐stressed conditions. The experiments were set‐up using a 10 × 10 alpha lattice design with two replications under water stress and non‐stress conditions. The following phenotypic traits were collected: number of days to heading (DTH), number of productive tillers per plant (NPT), plant height (PH), days to maturity (DTM), spike length (SL), kernels per spike (KPS), thousand kernel weight (TKW), root biomass (RB), shoot biomass (SB), root to shoot ratio (R:S) and grain yield (GY). There was significant (p < 0.05) variation for grain yield and biomass production because of genotypic variation. The highest grain yield of 247.3 g/m² was recorded in the genotype LM52 and the least was in genotype Sossognon with 30 g/m². Shoot biomass ranged from 830 g/m² (genotype Arenza) to 437 g/m² (LM57), whilst root biomass ranged between 603 g/m² for Triticale and 140 g/m² for LM15 across testing sites and water regimes. Triticale also recorded the highest R:S of 1.2, whilst the least was 0.30 for wheat genotype LM18. Overall, drought stress reduced total biomass production by 35% and R:S by 14%. Genotypic variation existed for all measured traits useful for improving drought tolerance, whilst the calculated R:S values can improve accuracy in estimating C sequestration potential of wheat. Wheat genotypes LM26, LM47, BW140, LM70, LM48, BW152, LM75, BW162, LM71 and BW141 were selected for further development based on their high total biomass production, grain yield potential and genetic diversity under drought stress.