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1.
外来杂草薇甘菊在不同群落中的种子生产特征 总被引:8,自引:1,他引:7
对3个群落花甘菊种群种子生产的3个特征即花序特征、种子产量和种子干粒重进行了分析。结果表明:不同种群中小花数、结实率、种子产量和种子干粒重存在显著差异,小花数变异范围为93281.6-154698.0朵/0.25m^2;平均结实率为25.75%一34.58%;平均种子产量的变异范围为23673.40—52616.71粒/0.25m^2;干粒重为0.0880—0.10208。在以有性生殖为主的种群和以无性生殖为主的种群中,前者的种子较大。结合薇甘菊种群对环境的适应对结果进行了讨论。 相似文献
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该研究选取六个多年生苦荞新品系,对春季、秋季直播与秋季再生其主要农艺性状进行调查。结果表明:(1)不同播种季节对多年生苦荞新品系主花序的花粉可育率、总结实率、有效结实率、植株株高、主茎粗、主茎分枝数、主茎节数、籽粒百粒重、单株粒数、单株产量的影响均达到显著或极显著水平;秋播主花序花粉可育率、总结实率、有效结实率、植株主茎分枝数、籽粒百粒重、单株粒数、单株产量均极显著高于春播;植株株高、主茎粗、主茎节数均极显著低于春播;主花序花朵大小、籽粒种子长宽比无显著差异。(2)不同种植方式对主花序花粉可育率、有效结实率、植株主茎节数及籽粒百粒重的影响达到显著或极显著水平;秋季再生主花序花粉可育率、籽粒单株粒数显著高于秋季直播;主花序有效结实率、植株主茎粗、主茎节数、籽粒百粒重显著低于秋季直播;主花序花朵大小、总结实率、植株株高、主茎分枝数、籽粒种子长宽比、单株产量无显著差异;相关分析表明,各生长季节下主花序有效结实率及单株粒数与单株产量的相关系数均最高。(3)所有参试品系中,1612-241秋季直播的单株产量显著高于其他品系; 1612-16、1612-33秋季再生单株产量较正季优势显著。该研究结果有助于筛选出适宜一季播种两季收获的优良品系,为今后多年生苦荞的选择育种提供线索基础。 相似文献
3.
高寒草甸小嵩草种群繁殖生态学研究 总被引:11,自引:0,他引:11
研究从繁殖生态学的角度对高寒草甸小嵩草(Kobresia pygmaea)种群进行了初步研究。结果表明:小嵩草属寒冷中生密丛短根茎地下芽植物,在高寒生境中采用以营养繁殖为主、有性繁殖为辅的繁策略,具体体现在以下几个方面:虽然小嵩草种子产量达4553.8粒/m^2,但种子萌发率较低,室内和野外萌发率分别仅有4%和1%,经氢氧化钠溶液和赤霉素溶液处理后的种子萌发率分别为1%和2%,而削去种皮后种子萌发率达52.6%,种皮坚硬是造成种子萌发率低的主要原因;进入种子库、保留至返青期且具有活性的种子仅占种子总数的24.35%,其室内萌发率仅有3%,而在野外理论实生苗仅为11.09个/m^2,与此相反小嵩草营养繁殖所形成的新个体数为6256.25个/m^2,远远多于种子萌发所形成的实生苗数。此外,小嵩草营养繁殖效力也远高于有性繁殖效力,营养繁殖效力占总繁殖效力的90.92%。 相似文献
4.
松嫩平原碱化草甸星星草种群营养繁殖及有性生殖的数量特征 总被引:14,自引:0,他引:14
根据对星星草单优群落独立株丛的大样本取样和对正常花序随机取样的调查与测定,分析了松嫩平原碱化草甸星星草种群的营养繁殖及有性生殖特征.结果表明,星星草种群诸营养繁殖数量性状之间有明显的规律性,丛植株数、丛地上生物量、丛生殖株数及丛生殖株重分别随丛径呈指数形式增加.星星草种群的圆锥花序大多为9—16个节,花序上各节位上的小穗数量呈γ密度函数分布.随着节位的增高,各节位上的小花数量呈Logistic曲线形式减少.小穗数和小花数均随节位增高呈饱和型指数曲线形式累积增长. 相似文献
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在水蔗草花序发育时期对花序喷施0.05g/L 2,4-D后.对水蔗草的花粉育性、结实率和无融合生殖的频率进行研究,结果表明:用0.05g/L 2,4-D处理,花粉育性和结实率与对照均没有明显的差异;无融合生殖的频率比对照显著下降。 相似文献
6.
中国东部假俭草种质资源多样性初步研究Ⅳ--同工酶分析 总被引:3,自引:0,他引:3
利用聚丙烯酰胺垂直凝胶电泳技术,对中国东部地区16份代表性假俭草种质资源两种同工酶进行了测定。结果表明,种源间过氧化物酶和酯酶同工酶酶谱在酶带数目、相对迁移率上均不尽相同,呈现出较丰富的多样性。 相似文献
7.
利用聚丙烯酰胺垂直凝胶电泳技术,对中国东部地区16份代表性假俭草种质资源两种同工酶进行了测定。结果表明,种源间过氧化物酶和酯酶同工酶酶谱在酶带数目、相对迁移率上均不尽相同,呈现出较丰富的多样性。 相似文献
8.
几种狼尾草属观赏植物在北京地区的生长特性 总被引:3,自引:0,他引:3
在北京地区气候条件下评价了狼尾草‘紫光’(Pennisetum alopecuroides(L.)Spreng‘Ziguang’)、绒毛狼尾草(Pennisetum setaceum(Forssk.)Chiov.)、羽绒狼尾草(Pennisetum villosum R.Br.ex Fresen)、狼尾草‘小兔子’(Pennisetum alopecuroides Desv.ex Ham‘Little Bunny’)和东方狼尾草(Pennisetum orientale Willd.ex Rich.)的田间生长状况、越冬存活率、根系生物量分布和繁殖特性。结果表明,这5种植物在北京地区气候条件下,能正常发芽、生长、抽穗、开花和结实。其中狼尾草‘紫光’、绒毛狼尾草植株高大,分蘖旺盛,盛花期花序高度达135CH和156cm,植株茎数达156和217个/株,地上生物量达608.7和535.3g/株,根系密集分布空间在距地表10~40cm,距茎秆0~30cm。狼尾草‘小兔子’和东方狼尾草株型矮小,株高为40cm,植株茎数分别为162和108个/株,地上生物量分别为124.2和39.8g/株,根系密集分布空间为距地表10~30cm,距茎秆15~30cm。羽绒狼尾草的茎秆半匍匐生长,分蘖能力强,盛花期花序高为79cm,植株茎数为389个/株,地上生物量高达619.9g/株,根系密集区为距地表0~30am,距茎秆0~30cm。狼尾草‘紫光’、狼尾草‘小兔子’和东方狼尾草在北京地区能安全越冬,成活率为100%,羽绒狼尾草和绒毛狼尾草在自然条件下不能越冬,成活率为0。5种狼尾草都可以播种和分株的方式扩繁。 相似文献
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濒危植物七子花的生殖构件特征 总被引:7,自引:1,他引:6
对濒危植物七子花(Heptacodium miconioides)的花枝构成及不同类型花序的结实状况进行了研究。结果显示:(1)在黄经洞(种群B),花枝的营养生长旺盛,单枝的花序数和花数多,平均为23.5个和278朵;在狮子岩坑(种群A).开多轮花的花序比例高.但花枝的花序数较少,单枝的开花数最少。(2)七子花的结实率很低.可育胚珠的平均结实率均在40%左右,且结实率与花序的开花数量呈显著的负相关关系。(3)花序类型对种子重量也有一定的影响,其中种群A的Ⅰ型花序所结果实的种子最大,但这些种子的胚也未发育完全。因此,七子花成为濒危物种的关键并不是结实的数量,而是结实的质量。 相似文献
11.
中国结缕草属植物( Zoysia spp.)地上部分形态类型多样性 总被引:14,自引:0,他引:14
通过对结缕草属 (ZoysiaWilld .)植物地上部分 18个形态性状的的聚类分析 ,将产于中国的 78份结缕草种质划分为 6组 ,结缕草 (Z .japonicaSteud .)和中华结缕草 (Z .sinicaHance)具有较典型的特征而各自成组 ,细叶结缕草(Z .tenuifoliaWilld .)和沟叶结缕草〔Z .matrella (L .)Merr.〕为一组、大穗结缕草 (Z .macrostachyaFranch .)和长花结缕草 (Z .sinicavar.nipponicaOhwi)为一组 ,另有两组为比较独特的类型。结缕草属植物叶表面被毛、叶长、叶宽等营养性状和生殖枝高度、小穗密度、小穗数量等生殖性状都有较大的变异 ,变异系数 13.75 %~ 5 8.74 % ,其中中华结缕草内部存在更大的变异 ,表明在中华结缕草种内选育更加容易获得优良种质或品种。主成分分析表明 ,小穗数、小穗长、小穗密度、小穗长宽比以及叶片宽度和叶片被毛发达情况是结缕草属形态分类的重要依据 ,其中叶片被毛发达情况可以作为区分结缕草和中华结缕草的简单依据 ;而生殖枝高度、穗长、叶长、花序柄长度 (1)和叶长宽比可作为研究结缕草属下种内分异的主要依据 相似文献
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栽培大豆和野生大豆耐盐性及离子效应的比较 总被引:36,自引:0,他引:36
以国际上常用的耐盐大豆(Glycine max L.)品种Lee68为对照,在发芽期和苗期两个阶段,利用发芽指数、指害指数和耐盐系数等指标对一年生具盐腺野生大豆(Glycine soja L.)和部分栽培大豆(Glycine max L.)及某些野生大豆品系或品种的耐盐性进行了比较,讨论了耐盐指标的可行性。从离子效应方面比较了Na^ 和Cl^-对大豆发芽率的影响,并对具盐腺野生大豆的耐盐机理进行了初步分析。结果表明,大豆品种的耐盐性在发芽期和苗期无一致相关性。轻度等渗胁迫下,Na^ 对种子发芽率的抑制作用大于Cl^-,而重度等渗胁迫下则相反。通过减少由根系吸收的Na^ 、Cl^-向叶片的运输,维持叶片中较高含量的K^ ,减轻盐离子毒害,可能是具盐腺野生大事耐盐的主要生理机制之一。 相似文献
14.
《Saudi Journal of Biological Sciences》2022,29(4):2800-2810
The realization of grain yield in wheat is decided by source-sink balance under prevailing environmental conditions. Management conditions like changing the sowing time influence the source-sink capacity through modification in agronomic traits. Therefore, this experiment was conducted to decipher the influence of spike architectural traits (SATs) on grain yield and to open avenues for further grain yield enhancement. Comparatively early sowing over timely sowing gives the advantage of realizing higher grain yield with a positive relationship with SATs namely spike length, spikelets per spike, individual spike weight, individual grain weight, number of grains per spikelet, grain length, and grain width of upper and lower spike portion. Confirmatory factorial analysis revealed that spike length, spikelets per spike, individual spike weight, grains per spikelet were having a significant effect in deciding grain yield in early sown. The presence of a significant effect of genotype by environment interaction over grain yield and SATs allows the exploitation of available genotypic and environmental variability for further yield enhancement. GGE analysis on transformed and standardized grain yield-trait (GY-trait) combinations was used in the selection of genotypes having high GY-trait combinations for both sowing times. In early sowing, WG 11 was the best for high GY with high individual spike weight; grain length and grain width at lower and upper parts of the spike; and shorter days to 50% flowering. Genotypes exclusively having the high GY-trait combination along with low values of remaining GY-trait combinations were also selected with genotype focused GGE approach. 相似文献
15.
Wheat grain yield consists of three components: spikes per plant, grains per spike (i.e. head or ear), and grain weight; and the grains per spike can be dissected into two subcomponents: spikelets per spike and grains per spikelet. An increase in any of these components will directly contribute to grain yield. Wheat morphology biology tells that a wheat plant has no lateral meristem that forms any branching shoot or spike. In this study, we report two novel shoot and spike traits that were produced from lateral meristems in bread wheat. One is supernumerary shoot that was developed from an axillary bud at the axil of leaves on the elongated internodes of the main stem. The other is supernumerary spike that was generated from a spikelet meristem on a spike. In addition, supernumerary spikelets were generated on the same rachis node of the spike in the plant that had supernumerary shoot and spikes. All of these supernumerary shoots/spikes/spikelets found in the super wheat plants produced normal fertility and seeds, displaying huge yield potential in bread wheat. 相似文献
16.
西藏小麦资源在都江堰试种的表现及评价 总被引:10,自引:0,他引:10
对125份来源于西藏的小麦地方品种进行农艺性状分析和评价。结果显示,西藏小麦植株高度总体偏高,少数适中。分蘖数多数在10个以下,少数偏多。穗长、小穗数的单位长度着生的小穗数存在明显差异,存在一些密穗类型和多小穗类型。多数小麦品种穗粒数不少,但千粒重明显偏低。性状相关分析表明,随着分集数增多、穗长增长、小穗数增多,株高有增加的趋势,而株高的增加又导致了千粒重的降低。小穗数多其穗长通常比较长。中时西藏小麦资源进行了评价、利用方式进行了探讨、在都江堰与西藏表现差异的原因进行了分析。 相似文献
17.
冬小麦产量性状的遗传效应分析 总被引:4,自引:0,他引:4
以农大139等7个冬小麦品种进行4×3不完全双列杂交,采用加性-显性及其与环境互作的遗传模型对亲本、F_1和F_2的株高、主穗穗长、单株穗数、主穗小穗数、千粒重和单株粒重6个性状进行遗传分析.结果表明,株高和主穗长主要受加性效应控制,而单株穗数、主穗小穗数、千粒重和单株粒重主要受显性×环境互作效应影响.矮2杂交后代易选到矮株,奥里生杂交后代易得到大穗材料,农林10号和奥里生的杂交后代分蘖力将加强,814的杂交后代小穗数增多,814杂交后代千粒重增高.所有产量性状未表现明显的杂种优势. 相似文献
18.
Grain number determination in durum wheat as affected by drought stress: An analysis at spike and spikelet level 总被引:1,自引:0,他引:1
Petros Vahamidis Andreas J. Karamanos Garyfalia Economou 《The Annals of applied biology》2019,174(2):190-208
Yield studies show that increases in grain yield are always accompanied by an increase in grain number and, hence, further increases in yield potential may require additional improvements in grain number. The improvement of modern durum wheat was mainly based on the introduction of semidwarf genes. A 2‐year field drought stress experiment, concerning two different genotype groups (landraces vs modern cultivars), was carried out under a rainout shelter in order (a) to assess the effect of water deficit on floret dynamics and grain number determination, (b) to explore the relationship between plant water status with grain number per spike and its components (i.e., spikelets per spike, fertile florets per spikelet and grain set) and (c) to quantify the importance of several plant traits in determining the final number of grains per spike and fertile florets per spike when the main source of variation is water availability. Compared to control (well irrigated), grain number per spike was reduced, depending on year, genotype and water availability level, by 12.4–58.7% and this reduction was evident almost in all spikelet positions along the spike. Although there were some doubts in the past about the increased sensitivity of semidwarf cultivars to drought stress, they were not confirmed from our results. In most of the cases, the variation in plant water status (by means of water potential index [WPI]) during floret primordia phase (FPP) explained most of the variance in grain number per spike, fertile florets per spikelet, grain set and fertile spikelets per spike. In general, increasing water stress intensity decreased grain number per spike by an average rate of 13.5 and 9.4 grains per 0.2 MPa decrease in WPI, in modern cultivars and landraces, respectively. However, seasonal and genotypic effects were evident by modifying the slopes of the linear regressions between WPI and the studied plant traits. Commonality analysis revealed that the number of fertile florets per spikelet was the best predictor of grain number per spike, indicating that there is still much space for further improvement for this trait in landraces. However, this trait has been clearly improved in modern cultivars, especially at the basal and central spikelets. Although the number of spikelets per spike was the best unique predictor of the number of grains per spike in modern cultivars, grain set presented the highest total effect. 相似文献
19.
Sink-limitation to yield and biomass: a summary of some investigations in spring wheat 总被引:10,自引:0,他引:10
Yield potential can be expressed as a product of light interception, radiation use efficiency (RUE), and the partitioning of biomass to grain yield, or harvest index (HI). Traits related to early or late light interception have not been shown to be associated with genetic improvement of spring wheat yield in favourable environments. It is, however, well established that yield improvement is largely a result of increased HI, although the most recent studies comparing genetic progress in HI over time in spring wheat indicate that it has not made any additional progress since the mid 1980s. These observations suggest that future genetic progress in yield will most likely be achieved by focusing on constraints to RUE. Considering the possibility that RUE may be influenced indirectly by sink limitation, it is apparent that biomass may be increased by increasing grain number, for example. Experiments with high yielding spring wheat lines containing the alien translocation 7DL.7Ag showed increased grains m‐2 (15%), yield (12%), and biomass (9%) compared with controls. The translocation was also associated with a larger investment in spike mass at anthesis (15%), more grains/spike (10%), and increased flag‐leaf photosynthetic rate during grain‐filling (20%). The data suggest that increased biomass in 7DL.7Ag lines was due to significantly increased RUE post‐anthesis, as a result of a larger kernel number (sink) that increased the demand for photosynthesis during grain‐filling. The hypothesis that increased photosynthesis and RUE may respond directly to a larger number of grains/spike was tested experimentally by imposing a light treatment during boot stage. The treatment was associated with a small increase (5%) in the proportion of biomass invested in spike mass at anthesis, reflected by on average three extra grains/spike at maturity. The treatment was associated with 25% more yield and 22% more biomass than controls, while carbon assimilation rate measured on flag‐leaves during grainfilling was 10% higher than controls. The results suggest that RUE can be increased indirectly by increasing sink strength and that the current yield limiting process in spring wheat is the determination of kernel number. Experimental data are presented on how spike fertility may be increased through breeding, for example by introgression of the multi‐ovary trait to increase grain number per spikelet. In addition, results of analysis of the physiological bases of genotype × year interaction in high yield environments are presented in the context of how such information can provide a focus for genetic studies of sink limitation. 相似文献
20.
Weiping Shi Linqi Yue Jingye Cheng Jiahui Guo Lulu Li Kaidi Xie Jiarui Dong Yanhao Xu Jie Guo Meixue Zhou 《Molecular breeding : new strategies in plant improvement》2018,38(12):146
Kernel number per spike (KNPS) is one of the key factors affecting wheat yield, which can be significantly reduced by lower fertility or sterility of the apical and basal spikelets. In this study, the spikelet number per spike (SNPS), thousand kernel weight (TKW), KNPS, total grain numbers of the top three apical spikelets (GNAS), and total grain numbers of the bottom three basal spikelets (GNBS) of 212 wheat lines were recorded from five different environmental conditions. These 212 accessions were genotyped using the 9K iSelect SNP Beadchip. A total of 3269 SNP markers were used for genome-wide association analysis (GWAS). One hundred twelve significant marker-trait associations (MTAs) were identified. Twenty-two MTAs were identified in at least two environments and two of them showed association with two or more grain setting properties. Different loci showed an additive effect with both GNAS and GNBS being much higher in the lines with more favorite alleles. Two SNP loci, wsnp_Ex_c31799_40545376 and wsnp_BF293620A_Ta_2_3, showed the largest effects on increasing KNPS through improved fertility of apical and basal spikelets, respectively. These MTAs have the potential to be used in future marker-assisted selection. 相似文献