棉花单一群体创“150”产量构成及其贡献率分析

单位面积铃数、单铃重和衣分是构成棉花产量的三个重要因素。单位面积铃数对创“１５０”（公顷２２５０ｋｇ,后同）产量的贡献率最大,单铃重和衣分次之。偏相关分析表明,单位面积铃数与单铃重和衣分呈极显著的负相关。增加单位面积铃数与提高单铃重和衣分是创“１５０”高产的不同主攻方向。主攻单位面积铃数时,实收密度不得低于４．６５万株·ｈｍ－２。选用高铃重高衣分优良品种,创高产的风险性较小。创高产群体要求生物学产量稳定在１５ｔ·ｈｍ－２以上,子棉经济系数稳定在０．３８３以上。     

Effect of Urea on Photosynthesis and Yield in Mungbean

The effect of foliar application of 0.5 % and 1.0 % urea solutions after flowering on photosynthesis and yield was examined in mungbean ( Vigna radiata [L.] Wilczek) var. PS 16. Urea applied plants sustained higher rate of photosynthesis, retained more leaf area and this led to more dry matter production and consequently the seed yield was increased by increasing the number of pods per plant. These results are discussed in relation to source-sink relationship in mungbean.     

高羊茅种子产量因子与产量的通径分析

采用多因素正交试验设计,通过大样本相关、通径和逐步回归分析后表明,高羊茅5个种子产量因子对种子产量的直接贡献大小排序为:生植枝数/m2＞小花数/小穗＞种子粒数/小穗＞单粒种子重＞小穗数/生植枝;提高小花数/小穗和种子粒数/小穗可最有效提高高羊茅的种子产量,其次是提高生植枝数/m2.     

扁蓿豆种子产量构成因子的分析

通过对扁蓿豆种子产量构成因子做相关、通径和回归分析，找出呼和浩特地区扁蓿豆种子产量构成因子中的限制性因子是生殖枝数／株；预测栽培扁蓿豆单株实际种子产量的模型为Y=1．651＋0．025X1。利用种子产量构成因子计算潜在种子产量、表现种子产量和实际种子产量。     

红菜苔种子大小和种皮颜色对种子质量及苔产量的影响

该试验就红菜苔种子大小和种皮颜色对种子发芽势、发芽率、简化活力指数以及红菜苔植株的熟性、株平均苔数、单株苔重、单位面积苔产量的影响进行了研究。结果表明：（１）大粒种子的简化活力指数、株平均苔数苔重及单位面积的苔产量均显著或及显著高于小粒种子，而且，大粒种子植株现蕾比小粒种子早４－５天。但种子大小对发芽势、发芽率无影响。（２）深褐色种子的发芽势、发芽率、简化活力指数均显著或及显著高于深红色和灰褐色程     

苜蓿种子产量及其构成因素的多样性研究

在2005-2006年连续两年在条播条件下对国内外62份苜蓿种质55个4龄苜蓿品种的种子产量及其构成因素的多样性和相关性进行了研究.结果表明所有参试的苜蓿品种间的种子产量差异比较大,生殖枝数/m2、每生殖枝花序数、每花序小花数、每花序小荚数,每小荚种子数品种间存在较大的变异,遗传多样性比较复杂.通过对两年的数据进行相关分析发现,种子产量与牛殖枝花序数在两年中相关均极显著,可以作为高种子产量品种选育的重要指标之一.实际种子产量占潜在种子产量百分比在品种之间和茬次之间均存在较大差异,而且发现两年中实际种子产量占潜在种子产量几乎均小于4%,绝大部分在1%～2%之间.研究发现千粒重与其它指标相关性不显著,国内品种千粒重表现比较大的变异,多数品种间千粒重差异较大,但国外品种间(除Jindera外)千粒重变异较小,品种间差异不显著(p>0.05).     

Peroxidase Activity in Relation to Plant Height and Seed Yield in Indian Mustard (Brassica juncea L. Coss)

Peroxidase levels were assayed in 12 genotypes and in 36 F₁cross progenies of Indian mustard ( Brassica juncea L. Coss) at twelve stages of development, starting from seed germination till seed formation. The levels of peroxidase activity and the coefficient of variation emphasized the role of differential enzyme activity at different stages of development. Genotypes were also evaluated for plant height and seed yield. The correlations of peroxidase activity in 24 h soaked seeds with plant height and seed yield were significantly positive while those of enzyme activity in 45 days old plants with these traits were significantly negative. The study suggests the changing role of enzyme at two critical stages of plant development.     

Physiological Investigation of the Impact of Nitrogen and Sulphur Application on Seed and Oil Yield of Rapeseed (Brassica campestris L.) and Mustard (Brassica juncea L. Czern. and Coss.) Genotypes

Field experiments were conducted to determine the physiological basis of the effects of N and S interactions on seed and oil yield of Brassica species. Five combinations of N and S (in kg ha⁻¹) 0S+100N (T₁), 40S+60N (T₂), 40S+100N (T₃), 60S+100N (T₄) and 60S+150N (T₅), were used for this purpose. Nitrate reductase (NR) activity and ATP-sulphurylase activity in the leaves were measured at various growth stages, as the two enzymes catalyse rate-limiting steps of the assimilatory pathways of nitrate and sulphate, respectively. The activities of these enzymes were strongly correlated with seed and oil yield. The highest nitrate reductase activity, ATP-sulphurylase activity and yield were achieved with the combination T₃ in both species. Any variation from this combination decreased the activity of these enzymes, resulting in a reduction of the seed and oil yield of Brassica species. The higher seed and oil yield achieved in these species at T₃ could be due to optimization of leaf soluble protein and photosynthetic rate, as these parameters are influenced by N and S assimilation.     

The Influence of Row Spacing and Seeding Rate on Seed Yield and Yield Components of Forage Turnip (Brassica rapa L.)

The effects of four row spacings (17.5, 35.0, 52.5 and 70.0 cm) and five seeding rates (50, 100, 200, 400 and 800 viable seeds m^?2) on seed yield and some yield components of forage turnip (Brassica rapa L.) were evaluated under rainfed conditions in Bursa, Turkey in the 1998–1999 and 1999–2000 growing seasons. Plant height, stem diameter, pods/terminal raceme, total pods/plant, seeds/pod and primary branches/plant were measured individually. The number of plants per unit area was counted and the lodging rate of the plots was scored. The seed yield and 1000‐seed weight were also determined. Row spacing and seeding rate significantly affected most yield components measured. The number of plants per unit area increased with increasing seeding rate and decreasing row spacing. Plant height was not greatly influenced by row spacing and seeding rate, but higher seeding rates reduced the number of primary branches and the stem diameter. The number of pods/main stem was affected by row spacing and but not by the seeding rate. Also, the number of seeds per pod was not affected by either the row spacing or the seeding rate. In contrast, the number of pods per plant clearly increased with increasing row spacing, but decreased with increasing seeding rate. The plots seeded at narrow row spacings and at high seeding rates were more sensitive to lodging. Seeding rate had no significant effect on seed yield in both years. Seed yield was similar at all seeding rates, averaging 1151 kg ha^?1. However, row spacing was associated with seed yield. The highest seed yield (1409 kg ha^?1) was obtained for the 35.0‐cm row spacing and 200 seeds m^?2 seeding rate combination without serious lodging problems.     

NaCl胁迫对甘蓝、白菜和油菜种子萌发的影响

为研究蔬菜种子吸收或外排Na+能力与其耐盐性的关系,采用非损伤微测技术检测了628甘蓝、青杂中丰白菜、苏州青油菜、茼蒿、上海鸡毛菜种子外Na+流速的动态变化.结果表明,在10mmol/L NaCl溶液处理下,甘蓝和茼蒿种子外排Na+,而白菜、油菜和鸡毛菜种子吸收Na+,其中,甘蓝、白菜和油菜种子对Na+吸收或外排的效果明显.随后以甘蓝、白菜和油菜种子为材料,在不同NaCl浓度下对种子萌发进行了实验,结果表明,随着NaCl浓度升高,甘蓝、白菜和油菜种子的发芽率、相对发芽率、发芽势和发芽指数都呈明显下降趋势.当NaCl浓度达到300mmol/L时,甘蓝、白菜和油菜种子的发芽率分别为37.33％、14.67％和10.00％,耐盐半致死浓度分别为323.73,241.68mmol/L和200mmol/L.初步说明种子可以通过增加Na+的外排,减弱高浓度Na+对种子的毒害作用.     

Drought Stress Effects on Seed Yield, Yield Attributes, Growth, Cell Membrane Stability and Gas Exchange of Synthesized Brassica napus L.

Drought stress effects on leaf gas exchange, cell membrane stability, seed yield and yield attributes of synthesized Brassica napus L. cv. Bangla kale and Bangla cabbage were compared. Drought stress treatments were imposed at early vegetative, late vegetative and flowering stages by withholding watering. Bangla cabbage produced greater pods/plant, larger seed size, greater total dry matter/plant, seeds/pot, and 17% greater yield than Bangla kale. The seed yield in plants stressed at early vegetative, late vegetative and flowering stages were 59, 74, 88% lower respectively, than watered plants. Drought stress reduced leaf photosynthesis by 67 to 97%. Bangla cabbage had 68% greater photosynthesis and 56% greater stomatal conductance than Bangla kale under stress at flowering stage. Leaf temperature was 1 to 2°C higher in stressed plants than watered plants. The cell membrane stability (CMS) increased up to 83% at flowering stage under stress compared to 21% under watered conditions. Although Bangla cabbage had high seed yield, yield attributes and photosynthesis under stressed conditions at flowering stage, its CMS values were lower than those of Bangla kale.     

密度及行距配置对‘丰油10号’生长发育、产量和品质的影响

为了探究‘丰油10号’在黄淮地区适宜的播种密度与行距配置。在河南省油菜主产区进行大田试验,比较不同种植密度及行距配置方式下,‘丰油10号’的物候期、叶片叶色值(specialty products agricultural division, SPAD)及开花期叶面积指数(leaf area index, LAI)、经济性状、产量和品质情况。结果表明：‘丰油10号’的生育期随着密度和行距的增大,逐渐缩短;叶片的SPAD值在蕾薹期和开花期随密度增大逐渐降低,随行距缩小而减小;植株LAI在开花期随着密度的增大先增后减,同一密度下,40 cm行距下较高;株高、一次有效分枝数、主花序的长度和角果数随密度的增加逐渐较小,分枝部位则升高,随行距的减小单株有效角果数下降,千粒重不受密度和行距配置的影响;籽粒产量和含油量随着种植密度的增加先增后减,籽粒产量在种植密度为42万株/hm²,40 cm行距下最高,为2734.6 kg/hm²,当行距缩小到20 cm,籽粒平均减产4.65%;籽粒芥酸和硫苷含量不随密度和行距改变发生变化。在其它栽培措施保持不变的情况下,建议‘丰油10号’在黄淮流域的种植密度控制在34.5万~49.5万株/hm²,行距设置为40 cm。     

Nutrient Management Effects on Light Interception, Photosynthesis, Growth, Dry-matter Production and Yield of Indian Mustard (Brassica juncea)

A field experiment was conducted on sandy loam acidic soil to study the effect of nutrient managements on light interception, photosynthesis, growth, biomass production and yield of Indian mustard [Brassica juncea (L.) Czern & Coss.]. Plant height, number of branches per plant, number of siliqua per plant, number of seeds per siliquae, 1000‐seed weight, seed and oil yield of Indian mustard improved at 100 % recommended rates of NPK (N‐P‐K at 80‐17.2‐33.2 kg ha^?1) + 10 t ha^?1 farmyard manure (FYM) (T₃) compared with 100 % NPK rate (T₂). It was also at par with 100 % NPK + 10 kg ha^?1 borax + 20 kg ha^?1 ZnSO₄ (T₆) and 50 % NPK + 10 t ha^?1 FYM +10 kg ha^?1 borax + 20 kg ha^?1 ZnSO₄ (T₁₀). The rate of photosynthesis increased due to appropriate nutrient management treatments (T₃, T₆ or T₁₀) with concomitant increase in photosynthetically active radiation, internal CO₂ concentration and rate of transpiration and decrease in stomatal resistance. Consequent upon the higher rate of photosynthesis, dry‐matter accumulation increased. The crop receiving nutrient treatment T₃ or T₆ maintained higher light interception ratio (LIR), leaf area index (LAI), biomass production, crop growth rate (CGR) and net assimilation rate (NAR) that resulted in greater rate of photosynthesis, harvest index and seed yield. Similarly, T₁₀ was equally efficient in registering greater LIR, LAI, CGR, NAR and seed yield of mustard. The average seed yields were 1692, 1683 and 1668 kg ha^?1 in T₃, T₆ and T₁₀, respectively, and these three treatments were significantly superior to T₂ (1332 kg ha^?1), control (723 kg ha^?1) and other treatments. Significantly greater seed oil contents of 41.30, 40.60 and 41.07 % were recorded in T₃, T₆ and T₁₀, respectively. Thus, significant improvement due to appropriate combination of NPK, FYM, borax and ZnSO₄ was observed for uptake of nutrients.     

Selection for Seed Yield in Lolium perenne L.*

Components of seed yield were estimated for each set of 100 plants derived from six varieties of Lolium perenne. Significant differences between the varieties were found for all components of seed yield, but the range was broader within each variety. An indirect selection of seed yield using the character seeds per spike produced a selection response similar to that obtained by direct selection on high seed yield per plant. A direct and indirect selection of characters estimated in small, drilled plots of topcross off-springs (F₁) was less successful than the selection based on the single plants. Spearman rank correlation coefficients between the single plants and their offsprings did not show significant agreement for seed yield. But altogether the results indicated that the increase of seed yield/area was about 6 % when 10 % of the best plants were selected.     

串叶松香草种子产量构成因子分析

采用方差分析、相关分析、通径分析和逐步回归分析对串叶松香草种子产量构成因子进行了研究,结果表明:在串叶松香草株高、每株生殖枝数、每株花序数、每花序种子数、千粒重和单株种子产量这6个产量因子中,除株高和千粒重在不同生长年限之间不存在显著差异外,其它因子均存在显著差异;每株花序数和每花序种子数与单株种子产量间存在极显著相关,是串叶松香草种子产量的主要影响因子;串叶松香草单株种子产量的回归模型为:Y=-87.50047+0.14578X3+4.19497X4(F=23.51,Pr0.0001)。     

Path-Coefficient Analysis of Seed Yield Components in Euphorbia lathyris L.

The interrelationships of seed yield components in Euphorbia lathyris L. have been studied by means of path-coefficient analysis. Two of seven components, ‘Number of flowers of primary inflorescence’ and ‘Number of flowers of secondary inflorescences’ proved to be of major importance through direct effects on ‘Total number of fruits’ as indicator of seed yield. Indirect effects generally arc being canalized via the same variables. Selection for seed yield is made possible through the relation between ‘Number of secondary branches’ and ‘Number of flowers of secondary inflorescences’.     

不同倒伏程度对夏玉米叶面积指数、产量及其构成因素的影响

以“郑单958”夏玉米为试材,通过田间小区试验,研究了抽雄期不同倒伏程度对夏玉米叶面积指数（LAI）、产量及其构成因素的影响。结果表明：随生育期推移,LAI逐渐减小,各处理差异显著,严重倒伏的A00处理后期LAI一直最小。随倒伏程度加重,穗长、穗粒数减少,百粒重下降,产量和生物产量降低;同时减产幅度增加,与未倒伏对照处理比较, A60、A45、A30和A00处理分别减产5.8%、24.3%、52.2%和89.9%。研究结果可为夏玉米高产栽培提供参考依据。     

密度对棉花产量及棉铃内部产量构成的影响

以杂交种中棉所75和常规种鲁棉研28为材料,从冠层、单株以及单铃内部几个不同层次深入研究了密度对产量及产量构成因子的影响。结果表明,密度显著影响棉花产量,且这种影响可追溯到单株,甚至单个棉铃内部的单个种子上。5.1万株和8.7万株·hm-2密度下皮棉产量无显著差异,但显著高于1.5万株·hm-2密度的产量。在该试验密度范围,随着密度增加,棉株上部果枝和外围果节的成铃率显著降低;铃重、单粒种子截面积和单铃内种子数随密度增加呈下降趋势;单粒种子上纤维质量与种子所处位置相关,在棉铃基部和中部其随密度变化差异较大。     

芸薹属油菜及其近缘属作物种皮纹饰亚微结构研究

由于种子表面具蜡质和脂肪,采用常规制样方法往往不能获得种皮纹饰的清晰图像,经二甲苯、石油醚严格脱蜡,脱酯后油菜种皮纹饰在扫描电镜睛清晰可见。本文比较分析了白菜型油菜（Ｂ．ｃａｍｐｅｓｔｒｉｓ,ＡＡ）,黑芥（Ｂ．ｎｉｇｒａ,ＢＢ）,甘蓝（Ｂ．ｏｌｅｒａｃｅａ,ＣＣ）,甘蓝型油菜（Ｂ．ｎａｐｕｓ,ＡＡＣＣ）、芥菜型油菜（Ｂ．ｊｕｎｃｅａ,ＡＡＢＢ）、埃塞俄比亚芥（Ｂ．ｃａｒｉｎａｔａ,ＢＢＣＣ）、油用