草地早熟禾种子产量构成因素的品种差异

对草地早熟禾 2 8个品种种子产量及性状进行了研究 .结果表明 ,2 8个品种间种子产量存在极显著差异 (P <0 .0 1) ,最高的品种为Balin和Monoply ,其产量达 6 4 3.4～ 6 5 0 .2kg·hm-2 ,为最低品种Elysee(90 .1kg·hm-2 )的 7.1倍 .生产性状相关分析表明 ,生殖枝数 /株、生殖枝高、花序长及小穗数 /生殖枝 4个性状为影响早熟禾种子产量的主要因素 .依据对种子产量及上述 4个性状测定值的聚类分析 ,可将 2 8个品种的种子生产性能分为极强、很强、强、中等、差和极差 6个类群 ,其中Monoply等 6品种为极强类群 ;Baronie、Balin和Sydsport、Entopper分别为很强和强类群 ;Nublue等 12品种为中等类群 ;Broadway等 4品种和Ram1、Elysee分别为差和极差类群     

内蒙古中东部草原不同生境克氏针茅（Stipa krylovii Roshev.）种群的形态差异分析

对内蒙古中东部草原分布的克氏针茅进行了种群内和种群间的形态差异分析。结果表明：（1）种群内不同的形态性状存在不同程度的差异;（2）种群间生殖枝中的一部分形态性状以及营养枝高度和营养枝干重均存在较大差异;（3）每穗小花数、每穗籽粒数、每穗小穗数、生殖枝高、穗干重、生殖枝干重、每穗种子重、种子重/生殖枝重比等性状的变化趋势相同,均表现为随生境条件变差而增加,即在生殖上投入增加以增大适合度;（4）主成分分析表明穗长、种子重/生殖枝重比、每穗小花数、每穗籽粒数、生殖枝高、基盘长、第二芒柱长、营养枝高、千粒重、芒针长是不同种群差异的主要指标。这些形态性状的差异可以看作克氏针茅对不同生境的适应性表现。     

青藏高原老芒麦落粒动态与农艺性状及地理分布关系研究

该试验以6份来自青藏高原东北缘老芒麦为研究材料,利用断裂拉伸张力(BTS)法评价其不同发育时期落粒率,并分析落粒率与其他农艺性状和地理信息的相关性,为老芒麦种子生产及低落粒种质筛选提供参考。结果表明:(1)老芒麦种子落粒率在抽穗后1周和2周较低,而在抽穗后3周与4周有所升高,在抽穗后5周种子落粒率最高(BTS=0.52N);供试材料ZHN03在测定时期内种子落粒率均低于其他材料,而材料XH09在抽穗后5周种子落粒率最高(BTS=0.33N)。(2)在种子脱落期间,低落粒与高落粒老芒麦的6个农艺性状变化趋势相似;老芒麦落粒性与5个农艺性状有密切关联,其中BTS值与穗长、小穗数和小穗小花数呈显著正相关关系,与芒长和千粒重具有极显著正相关关系。(3)老芒麦穗长与纬度间具有极显著负相关关系,芒长与纬度间具有显著负相关关系;千粒重与经度间具有极显著负相关关系,与海拔间具有极显著正相关关系;BTS值与小穗数呈显著正相关关系,与芒长和小穗小花数呈极显著正相关关系,而与地理分布并无显著相关性。(4)依据农艺性状可将供试材料分为3类,第Ⅰ类(HZ02、LT04与XH09)材料落粒较高,第Ⅱ类材料(MQ01与LQ03)具中等落粒性,第Ⅲ类为落粒最低的ZHN03。研究发现,供试老芒麦落粒性随种子成熟而增加;落粒率因材料及种子发育时期不同而有所变化,且在抽穗后4~5周各材料间的落粒性差异显著;老芒麦的落粒性与其穗长、小穗数、芒长、千粒重和小穗小花数存在较密切的相关性。     

亏缺灌溉对干旱区两种乡土植物种子生产性能及其水分利用效率的影响

科学灌溉对植物种子生产具有重要意义。本研究以荒漠草原优良乡土植物沙芦草和牛枝子为对象,以充分灌溉为对照,探究不同生育时期亏缺灌溉对两种牧草种子生产和水分利用效率的影响。结果表明: 与对照相比,亏缺灌溉下两种植物土壤含水率下降,其中沙芦草土壤含水率下降主要发生在0～60 cm土层,牛枝子土壤水分下降未出现明显的分层现象。亏缺灌溉下沙芦草种子产量各构成因子差异均显著,开花期亏缺灌溉种子产量最高;牛枝子仅生殖枝数、小花数和荚果数差异显著,种子产量各处理差异不显著。相关分析显示,沙芦草种子产量与生殖枝数(r=0.776)、小穗数(r=0.717)呈显著正相关;牛枝子花序数与生殖枝数呈极显著负相关(r=-0.685),与小花数呈显著正相关(r=0.412)。与充分灌溉相比,亏缺灌溉下两种乡土植物种子生产耗水量减少,水分利用效率提高,其中,沙芦草开花期亏缺灌溉水分利用效率提高最多(32.9%);牛枝子分枝期亏缺灌溉提高最多(27.4%)。因此,适当亏缺灌溉可以提高两种植物水分利用效率。从水分利用效率和种子产量来看,干旱区沙芦草和牛枝子种子人工繁育时可采取亏缺灌溉,适宜亏缺的生育期分别为开花期和分枝期。     

恢复措施对退化草地羊草种群有性生殖数量特征的影响

在封育和翻耙处理的退化羊草草地上,对羊草种群有性生殖的数量特征进行了比较研究．结果表明,翻耙样地羊草种群密度下降显著,生殖蘖密度变化不显著,生殖蘖穗长、节间长、生殖生长比率、穗节数、小穗数、小花数、饱满籽实数和结实率都有显著增长,籽实产量、净籽实重和千粒重分别是封育样地的2．68、3．49和1．3倍．在翻耙样地中,羊草种群发育有复小穗的生殖蘖比封育样地多16％,生殖蘖上复小穗的数量也显著增加,生殖蘖以相对少的小穗,生产了较多的小花和更多的籽实来提高种群的籽实产量．两个样地中羊草种群的生物量生殖分配在种群对生殖蘖RA1、生殖蘖对穗序RA4、穗序对籽实RA6 3个层次上无显著差异,而种群对穗序RA2、生殖蘖对籽实RA5的生殖分配差异显著,种群对籽实RA3的生殖分配差异极显著．     

双岛湾大叶藻的有性生殖特征

对威海双岛湾大叶藻(Zostera marina L.)种群的有性生殖特性进行了研究。结果表明:该水域中,大叶藻种群于3月下旬或4月上旬进入生殖枝始现期,5月上旬进入始花期,6月下旬进入种子散落高峰期,7月上旬进入生殖枝死亡始期,7月下旬生殖期结束,其有性生殖物候进程与水温密切相关,15℃是其开花适宜水温;生殖枝的侧枝数和扇状聚伞花序数在进入始花期时达到最大,分别为4.4和4.9个·株-1,佛焰苞数和生殖枝高度均在种子散落始期最大,分别为18.6个·株-1和96.2 cm,种子败育率较高,平均为40%,成熟种子产量为44.8粒·株-1;生殖枝密度在始花期时达到最大,为64株·m-2,生殖枝分化率平均仅有12.6%,有性生殖期间营养枝密度和种群总密度的下降幅度超过40%;生殖枝生物量在初果期达到最大(27.9 g·m-2),从始花期至种子散落高峰期平均种群生物量分配格局为地下部38.4%,营养枝52.4%,生殖枝9.2%,生殖分配较低,成熟种子产量为1859粒·m-2。     

天山北坡野生无芒雀麦的表型性状

为揭示新疆野生无芒雀麦的表型变异规律,采用变异系数、相关性、主成分分析等方法对采自天山北坡5个典型地区450株无芒雀麦的13个表型性状指标进行分析。结果表明:(1)天山北坡野生无芒雀麦存在变异,但变异系数较小,仅为0.294。(2)地区间无芒雀麦表型性状变异水平大于地区内变异水平,且天山北坡中段的变异程度与东段、西段相比差异较大;中段的变异程度随海拔的升高而增大,东段和西段则相反。(3) 13个性状指标在地区间变异范围广,最大的为分蘖数;性状指标与经度、纬度呈正相关,年均温度、年均降水量仅与穗长、根长等性状呈显著相关。(4)地区间表型性状的差异主要来源于生殖枝高度、穗长、叶长、叶宽等。(5)天山北坡中段的无芒雀麦株型较大,且大株型主要来自低海拔。综上所述,天山北坡中段气候更适宜野生无芒雀麦的生长,且低海拔的无芒雀麦生长情况优于其他两个海拔。     

秦岭南坡短柄枹栎和锐齿槲栎的种子产量和种子大小及其与昆虫寄生的关系

【目的】为了解昆虫寄生特征与短柄枹栎 Quercus glandulifera 和锐齿槲栎 Quercus aliena var. acuteserrata 的种子产量及种子大小的关系。【方法】本研究于2011和2012年在秦岭南坡佛坪国家自然保护区,对短柄枹栎和锐齿槲栎种群的种子产量和昆虫寄生特征进行了野外调查研究。【结果】2年中短柄枹栎、锐齿槲栎种子雨密度和种子产量均差异明显,2011年短柄枹栎种子雨密度和种子产量分别为145.76±24.56粒/m²和74.97±11.56粒/m²,分别显著高于2012年的64.09±9.61粒/m²和34.30±3.51粒/m²;2011年锐齿槲栎种子雨密度和种子产量分别为238.88±43.97粒/m²和117.34±18.76粒/m²,分别显著高于2012年的112.00±19.20粒/m²和55.96±19.20粒/m²。2011年短柄枹栎和锐齿槲栎的种子产量中完好种子所占比例分别为49.73%和50.73%,分别显著高于2012年的38.69%和44.28%;而2011年虫蛀短柄枹栎和锐齿槲栎种子所占比例分别为28.05%和19.31%,分别低于2012年的39.77%和26.63%,但并无显著差异。2011和2012年,短柄枹栎和锐齿槲栎虫蛀种子个体均显著大于完好种子,且2011年二者虫蛀种子所含幼虫数与种子大小的相关性显著,2012年二者相关性不显著。【结论】短柄枹栎和锐齿槲栎种子的虫蛀率与种子产量有一定的关系,即在种子产量较低年份,虫蛀率有升高趋势,反之有降低趋势。同时,昆虫对这两种栎树种子中个体大的种子有寄生选择偏好,同时虫蛀种子所含幼虫数与种子大小也有一定的关系,即种子越大,所含昆虫幼虫数就越多。     

沙埋对无芒雀麦种子萌发和幼苗生长的影响

研究了沙埋对浑善达克沙地植物群落中多年生禾草无芒雀麦种子萌发、出苗和幼苗生长的影响.结果表明:无芒雀麦种子能在深度≤12cm的沙埋中萌发,≤8cm的沙埋中出苗.在此范围内,随着沙埋深度的增加,无芒雀麦种子的萌发率和出苗率逐渐降低.沙埋深度在植株高度的33%时,无芒雀麦1周龄和2周龄幼苗均全部存活,且总生物量≥对照(未沙埋幼苗);当沙埋深度增至植株高度的66%时,1周龄和2周龄幼苗的存活率分别降至70%和25%,生长也受到抑制;而遭受全部沙埋时,1周龄和2周龄幼苗均不能存活.遭受沙埋后,无芒雀麦幼苗分配较多的生物量用于地上部分的生长,其生物量分配模式改变可能是无芒雀麦幼苗对沙埋环境的重要适应对策.     

青藏高原地区不同老芒麦种质资源生产性能评价

为选育适应青藏高原高产优质的老芒麦(Elymus sibiricus L.)品种,以青藏高原不同生态区域采集的11份老芒麦种质资源为对象,以国审登记品种青牧1号和同德老芒麦为对照,进行了连续3年的种子生产性能评价,为进一步选育种用型老芒麦材料提供依据。结果表明:(1)各材料在不同年份间种子产量均存在显著差异(P0.05),其中以I-1-5-13和I-1-5-19产量表现最优,平均产量达到1494.93 kg/hm2和1386.82 kg/hm2,较青牧1号老芒麦高81.49%和68.36%,较同德老芒麦高90.92%和77.11%。(2)随种植年份的增加,老芒麦种子产量呈下降变化。从种子稳产性来看,I-1-5-47和I-1-5-50两份材料3年内均表现为高产稳产,均可作为种用型老芒麦进行重点培育。(3)从各材料种子产量与产量性状相关性分析结果来看,单序籽粒数、种子长、小穗数、穗长和单序籽粒重与种子产量显著正相关(P0.05),其中单序籽粒数与种子产量间的正相关最大(相关系数为0.809),且其对种子产量增产的直接效应最大,可作为种用型老芒麦种子产量评价的关键性状。(4)13份材料种子产量及产量性状的聚类分析可将其分为3个类群:第I类群来源于海拔较高地区,平均海拔为3696 m,其产量表现中等;第Ⅱ类群材料来源于平均海拔为3244 m的低海拔地区,其种子产量高;第Ⅲ类群材料来源于高海拔地区,平均海拔为4392 m,其种子产量低。     

不同群落中四川大头茶 (Gordonia acuminata)花粉游离脯氨酸含量与种子产量

 四川大头茶(Gordonia acuminata)是缙云山亚热带常绿阔叶林的优势树种之一。对缙云山3种不同群落中四川大头茶的花粉游离脯氨酸含量和果实的种子产量进行了研究,发现花粉游离脯氨酸含量和每果种子产量在同一群落中的不同龄级四川大头茶个体间没有差异,但在不同群落间表现出差异。常绿阔叶林中的四川大头茶个体具有最高的花粉游离脯氨酸含量和每果种子产量,四川大头茶纯林中的次之,针阔混交林中的最低。分析发现,四川大头茶花粉游离脯氨酸含量与果实的种子产量有密切的正相关关系,花粉中的游离脯氨酸含量可以作为一种预测和比较相同地区不同生态环境中四川大头茶种子产量的指标。     

Presowing Seed Treatment with Cytokinins and Its Effect on Growth, Photosynthetic Rate, Ionic Levels and Yield of Two Wheat Cultivars Differing in Salt Tolerance

The effects of presowing seed treatment with different concentrations of cytokinins （kinetin and benzylaminopurine; 100, 150, and 200 mg/L） on growth, photosynthetic capacity, and ion homeostasis were investigated in two spring wheat （Triticum aestivum L.） cultivars, namely MH-97 （salt sensitive） and Inqlab- 91 （salt tolerant）. Primed and non-primed seeds were sown in a field in which NaC1 salinity of 15 dS/m was developed. Of the different concentrations of priming agents tested, the effect of a moderate concentration of kinetin （150 mg/L） was very pronounced, particularly in improving growth and grain yield, in both cultivars. In addition, priming with kinetin alleviated the adverse effect of salt stress on gaseous exchange characteristics （net CO2 assimilation rate and water use efficiency） in both cultivars. Seed priming with a moderate concentration of kinetin also altered the pattern of accumulation of Na^＋ and Clˉ in the shoots, irrespective of the wheat cultivar, under conditions of salt stress. However, all other priming agents at the different concentrations tested did not show any consistent effect on ion levels, except hydropriming, which increased K^＋ levels in the shoots of both cultivars under salt stress. In conclusion, a moderate concentration of kinetin showed a consistent effect in altering the growth and grain yield of both wheat cultivars, which was related to the beneficial effects of kinetin priming on water use efficiency and photosynthetic rate under conditions of salt stress.     

The Effect of Temperature on Seed Set and Seed Development in Detached Spikelets of Perennial Ryegrass (Lolium perenne L.)

In perennial ryegrass seed yield is low. Pollination, fertilizationand early stages of seed development are critical periods forthe realization of the yield potential. As intact plants aredifficult to handle, we used detached spikelets to study effectsof temperature and genotype on seed set and seed development. Plants of four cultivars were grown in pots. Just prior to flowering,spikelets were detached from the ears and put on water. Afterpollination, various spikelets of each plant were placed atdifferent temperatures (14/14, 17/12 or 20/15°C). Sevendays after pollination the percentage seed set and the lengthof the developing seeds (caryopses) were assessed. Only floretsin the four basal positions were used. For each cultivar an analysis of variance for unbalanced datawas carried out. There were highly significant difference amonggenotypes for seed set and caryopsis length. There was no evidencefor genotypic variation for tolerance to low temperatures. Neithertemperature nor floret position had an effect on seed set. Thecaryopsis length, however, increased with increasing temperatureand basal florets produced longer caryopses than distal florets.The detached spikelets proved to be a useful experimental tool.Copyright1993, 1999 Academic Press Lolium perenne L., perennial ryegrass, seed yield, seed set, detached spikelets culture, temperature, floret position     

Seed and seedling vigour in relation to crop growth and yield

In theory, seed germination, vigour and size (three aspects of seed quality) may influence crop yield through both indirect and direct effects. The indirect effects include those on percentage emergence and time from sowing to emergence. These influence yield by altering plant population density, spatial arrangement, and crop duration. Direct effects on subsequent plant performance are more difficult to discern. A number of different approaches to testing the hypothesis that seed quality affects subsequent plant performance (implicit in some definitions of vigour) are illustrated. The results show that it is possible to detect such effects in some circumstances.     

Seed dispersal in Erythronium grandiflorum (Liliaceae)

Primary and secondary seed dispersal was investigated for the glacier lily Erythronium grandiflorum in the Colorado Rocky Mountains. These heavy seeds have no obvious adaptations for biotic or abiotic dispersal, but can be thrown short distances when the dehiscent fruits are shaken by wind. We used sticky traps to measure primary transport of seeds up to 1 m away from individual plants. A seed cafeteria experiment examined the role of ants and rodents in secondary seed transport. Primary dispersal by wind was positively skewed and median transport distances were influenced by variation in plant height. Secondary dispersal was negligible compared to Viola nuttallii, an elaiosome-bearing species. Thus, seed dispersal was highly restricted in E. grandiflorum, and a 1 m radius encompassed the modal section of the seed dispersal curve. The seed dispersal component of gene flow was quantified and combined with previous measurements of pollen flow to yield a more complete estimate of Wright's neighborhood size, N _e, for E. grandiflorum. The lack of a special seed dispersal mechanism in E. grandiflorum is discussed in terms of a source-sink model for seedling establishment with respect to distance from the parental plants.     

Pyrenophora graminea on Winter Barley Seed: Effect on Disease Incidence and Yield Losses

Field experiments were carried out in 1982–83 and 1983–84 in Northern and Central Italy (3 locations) in order to investigate the effect of different levels of seed infection of Pyrenophora graminea on disease incidence and yield losses in ‘Perga’ winter barley. Six levels of natural seed infection, assessed by the deep-freezing blotter method have been compared in 8 row-plots, 7.5 m long, arranged in randomized blocks with 4 replications. The percentage of infected plants and tillers has been recorded in all locations and the yield in two of them. A highly significant correlation was found between seed infection, plant infection, tiller infection and yield reduction. Major ratios found were: infected seeds/infected seedlings 1: 0.4, infected tillers/yield loss 1: 0.9, infected seeds/yield loss 1: 0.3. The threshold of seed infection at which production was not significantly different from the healthy control was 14%. Therefore seed treatment is advisable, under the conditions of Northern and Central Italy, when the percentage of seed infection in commercial seed lots is above this level. A tolerance near zero is recommended in prebasic and basic seeds.     

Influence of Salt Stress on Growth, Ion Accumulation and Seed Oil Content in Sweet Fennel

A greenhouse experiment was conducted to assess the effect of 25, 50, 75, and 100 mM NaCl on growth, ion accumulation, seed yield, and seed oil content in 67-d-old plants of Foeniculum vulgare Mill. Increasing NaCl concentration caused a significant reduction in fresh and dry masses of both shoots and roots as well as seed yield. Na⁺ and Cl^– in both shoots and roots increased, whereas K⁺ and Ca²⁺ decreased consistently with the increase in NaCl concentration. Plants maintained markedly higher Ca²⁺/Na⁺ ratios in the shoots than those in the roots, whereas that of K⁺ /Na⁺ ratios remained almost uniform in both shoots and roots. Proline content in the shoots increased markedly at the highest NaCl concentration. Oil content in the seed decreased progressively with increase in salinity.     

The Dynamics of Seed Bank on Shapotou Artificially Stabilized Dunes

There were 46 species belonging to 17 families in the soil seed bank on Shapotou artificially stabilized dunes. Compositae was the family with most species '(11 species) and the others were Chenopodiaceae (7 species), Gramineae (7 species), Leguminosae (4 species), etc. 33.3 % of the species lived in the community also had seeds in soil. The seed production of Artemisia ordosica, Hedysarum scoparium, Caragana korshinskii was 545.57 ± 676.73 grains/m2. 6.67 ±13.74 grains/m2. 0. 032±0. 024 grains/m2, respectively. The seeds of A. ordosica were not destroyed by pests, but 31.9%, 83.29% of the seeds of H. scopariurn. C. korshinskii respectively were destroyed by pests. Under the most suitable burying depth, the cumulative seed germination rate of A. ordosica, H. scoparium, C. korshinskii were 78. 3%, 66.7%. 85.0%, respectively. The rate of germination was in the order of: A. ordosica>H, scoparium>C, korshinskii. The vegetation succession would tend towards community mainly consisted of A. ordosica, Bassia dasyphylla, Eragrostis poaeoides, etc.     

Yield and composition of soybean seed as a function of potassium supply

Summary A reduction in K supply to soybean plants to deficiency levels during both vegetative and reproductive development resulted in reductions not only in yield, but also in oil and K concentrations in the seed and a concomittant increase in seed protein concentration. Correlations between mean fruit yield and oil, protein and K concentrations, over a wide range of K regimes, were 0.97, −0.94 and 0.98, respectively. When K supply was increased well above the level necessary to produce maximum yields,i.e. luxury consumption, there was no significant change in K concentration in the seed, indicating a high degree of control in the movement of K to the developing seed under high K regimes. When the K supply to the plant was limiting, the rate of accumulation of oil and carbohydrate fractions, but not of seed protein, declined during the latter part of podfilling. This resulted in a fall in the C/N ratio in the non-structural seed components during this part of seed development. Depriving plants of K only during seed development had no effect on seed composition or yield, whereas resupplying K to deficient plants after anthesis resulted in almost the same seed composition and yield as that which occurred with control plants. Possible mechanisms whereby K deficiency influences soybean seed composition and yield are discussed in terms of movement of carbohydrate and nitrogen to the seed. We suggest that potassium-deficient soils are likely to produce crops with low yields and low seed oil levels; the crop may respond to K fertilizers as late as anthesis.     

Path and ridge regression analysis of seed yield and seed yield components of Russian wildrye (Psathyrostachys juncea Nevski) under field conditions

The correlations among seed yield components, and their direct and indirect effects on the seed yield (Z) of Russina wildrye (Psathyrostachys juncea Nevski) were investigated. The seed yield components: fertile tillers m(-2) (Y(1)), spikelets per fertile tillers (Y(2)), florets per spikelet(-) (Y(3)), seed numbers per spikelet (Y(4)) and seed weight (Y(5)) were counted and the Z were determined in field experiments from 2003 to 2006 via big sample size. Y(1) was the most important seed yield component describing the Z and Y(2) was the least. The total direct effects of the Y(1), Y(3) and Y(5) to the Z were positive while Y(4) and Y(2) were weakly negative. The total effects (directs plus indirects) of the components were positively contributed to the Z by path analyses. The seed yield components Y(1), Y(2), Y(4) and Y(5) were significantly (P<0.001) correlated with the Z for 4 years totally, while in the individual years, Y(2) were not significant correlated with Y(3), Y(4) and Y(5) by Peason correlation analyses in the five components in the plant seed production. Therefore, selection for high seed yield through direct selection for large Y(1), Y(2) and Y(3) would be effective for breeding programs in grasses. Furthermore, it is the most important that, via ridge regression, a steady algorithm model between Z and the five yield components was founded, which can be closely estimated the seed yield via the components.