Physiological Basis of Irrigation Scheduling for Seed Production in Egyptian Clover Syn. Berseem (Trifolium alexandrinum L.) Crop

A field experiment was conducted to find out the critical physiological stages of irrigation schedules inducing better growth, physiological efficiency and seed yield potential of berseem ( Trifolium alexandrinum L., Var. S-99-1). For this purpose eight irrigation treatments were made comprised of four treatments of three irrigation (W₁, W₂, W₃ and W₄), three treatments of four irrigation (W₅, W₇ and W₈) and one treatment of five irrigation (W₆) at various physiological stages i. e. regeneration, flower initiation, full bloom, seed initiation and advance seed development stage.
Thus based on the experimental results the physiological role of watering in berseem seed production could be discussed as:
With-holding of irrigation either at regeneration or at full bloom stage developed potential water stress in plants as indicated by high proline content of irrigation treatments — W₄, W₁ and W₇; and further brought out disturbance on the formation of carotene, synthesis of water soluble sugar and translocation of sugar towards reproductive organs during grain development stage. These stresses adversely affected the plant growth and flowering behaviour. The irrigation at seed initiation stage increased the seed yield. Continuous irrigation did not appear to be useful. Thus it can be concluded that irrigation at three critical physiological stages i. e. regeneration, full bloom and seed initiation was found to be essential for obtaining potential seed yield of berseem.     

Effects of harvest management on growth dynamics, forage and seed yield in berseem clover

Berseem clover (Trifolium alexandrinum L.) is an annual forage crop widely grown in Mediterranean environments. However, there is little information available on the patterns of accumulation and partitioning of assimilate in berseem and how this varies with harvest management, plant ontogeny or is influenced by genotype. Field experiments were conducted in Foggia (Italy) during three growing seasons (1991–92, 1992–93 and 1993–94), with the aim of evaluating the effects of different harvest managements on growth dynamics, forage yield and seed yield of one population of Egyptian (cv. ‘Giza 10’) as well as Italian (cv. ‘Sacromonte’) origin. Cutting treatments were applied at three different plant ages: sixth internode elongation (A), early flowering (B), and uncut control (C). The growth and development of the shoot and root systems were followed by destructive harvests made at about 5-day intervals during 9 weeks in spring in all treatments. Seasonal growth pattern, determined as dry matter accumulation, forage yield and seed production were greatly influenced by harvest management. The maximum value (20.5 g per plant on average) of dry weight was reached at about 250 days after sowing for treatment C. Defoliation induced a decrease of crown and root dry matter, however, as shown by the allometric relationships, the growth of roots and shoots was closely correlated and in most cases, shoot growth was higher than root growth and stem relative growth rate (RGR) was higher than leaf RGR. Berseem clover is a defoliation-tolerant species because after cutting, regrowth was accompanied by higher values of leaf-stem ratio (LSR), RGR and stem elongation rate (SER) than in control plants. The highest value for total forage yield (1.6 Kg m⁻²) and seed yield (60.5 g m⁻²) were obtained in treatment B and A, respectively. Plants cut at the sixth internode elongation showed a good seed yield and a small decrease (15%) in total forage yield as regards treatment B. Therefore, treatment A appeared the most favourable for obtaining double utilization (forage and seed yield) in a berseem crop. Berseem plants were greatly influenced by harvest treatments applied, but the response did not vary according to the genetic characteristics of the two cultivars examined.     

Selection for Seed Yield Production of Egyptian Clover (Trifolium alexandrinum L.) C. V. Fahl

Modified mass and family selection for seed yield production of berseem clover (Trifolium alexandrinum L.) c.v. ‘Fahl’ were applied for two generations. Two hundred plants (5 % intensity of selection) were selected for seed yield in the first season, 1985/86. In the second season, 1986/87, selection between and within half-sib families was practiced. In addition, equal parts of seeds from each of the 200 selected plants were bulked to form the C₁ modified mass selection; after establishing, the same procedure was adopted to form the C₂ generation. The cycles 1 and 2 of half-sib families and modified mass selection along with the base population family were evaluated for forage and seed yields. The realized gains from modified mass selection were 6.03 and 9.51 % for fresh forage yield, 5.57 and 10.86 % for protein yield and 13.23 and 16.19 % for seed yield in cycles 1 and 2, respectively, over the base population. The realized gain from family selection in cycle 2 as a percentage of the base population mean amounted to 11.32, 13.35, 17.47 and 3.15% for forage, protein, and seed yield and seed index, respectively. The broad sense heritability, as estimated from the variance components was 89.63, 63.03, and 76.67 % for dry forage, seed yield and seed index, respectively. Although, all these five traits (fresh, dry, protein, and seed yield and seed index) had positive correlation with each other, weak correlations were found between seed yield and forage yields. Furthermore, close associations were found among forage yield traits.     

云南籼稻每公顷15吨高产的产量及其结构分析

本文利用ＩＲ７２汕优６３等材料,在云南永胜县涛源乡高产环境下,对高产品种的产量及其构成因素分析研究表明,高产品种的结实率与产量呈极显著的正相关,相关系数为０．８１８１;有效穗与穗粒数呈显著负相关,有效穗、穗粒数、结实率和千粒重对产量的直接效应均为正值,其中以结实率的影响力最大,直接通径系数为０．７９７９。穗数、大穗型和中间型的品种（组合）均能获得１５t/hm^2的产量,但穗粒协调的中间型品种更易获得１５t/hm^2的高产。云南涛源获得每公顷１５t以上产量就在于高水平的穗数群体下,仍能协调与穗粒数及产量的关系。使得粒数和粒重达到相当的水平,１９９６年汕优６３获得１５t/hm^2产量的产量结构为,每平方米穗数489,每穗实粒数101．4千粒克30．7g;桂朝2获15．18t/hm^2的产量结构为每平方米穗数433,每穗实粒数126．2,千粒重27．3g。     

Phenotypic Variability for Bio-Agronomical Traits in Berseem (Trifolium alexandrinum L.) Populations of the Meskawi Botanical Group

The phenotypic variability and adaptability for bio-agronomic traits in berseem populations (Trifolium alexandrinum L.), was evaluated. The number of genotypes was 32 (26 of southern Italy origin and 6 Egyptian). They were evaluated under field conditions for two years (1989–90) in Foggia (Italy) adopting different cutting regimes: at 7–8th inter-nodes stem length, beginning of flowering, and no cutting. The genotypes of the Italian origin appeared to be better adapted when the cut was applied in the early stage of development, and more productive in seed yield. The Egyptian populations were most productive in forage in the later cuts and had a higher seed weight. The range of variation among the bio-agronomical traits was higher when the cut was applied at early flowering. The traits with wider range of variation were: dry matter, plant height at cut, regrowth at the fourteenth day after cut, tiller density and seed yield. Considering a multiplicative selection index, 6 populations were well adapted and could be used as parents in breeding programs and in extended farm cultivation.     

昆虫授粉对芝麻产量构成因素的影响

为探索芝麻花期访花昆虫授粉效果,更好地利用昆虫为其授粉提高产量。本研究利用全封闭、半封闭、开放3个处理对芝麻花期访花昆虫数量及产量构成因素进行调查和分析。结果表明：蜜蜂是芝麻主要的传粉昆虫,占总访花昆虫数量的78.69%~88.78%。通过芝麻盛花期蜜蜂访花次数可看出,1d当中蜜蜂访花高峰主要集中在9∶00-10∶30和15∶00-16∶30两时段。昆虫授粉可显著增加半封闭区、开放区芝麻单株蒴果数、每蒴粒数、千粒重、单株产量、小区产量,与全封闭区（CK）相比分别提高了7.06%~17.58%、10.48%~16.83%、2.19%~5.13%、11.24%~20.86%、10.12%~20.85%。因此,在芝麻杂交制种和栽培生产过程中,人为增加传粉昆虫数量对提高制种效果和增加芝麻产量具有重要意义。     

Effect of generation of inbreeding, cutting treatment and year on agronomic traits in berseem populations

The selfing effect in berseem clover (Trifolium alexandrinum L.) was analysed by comparing generation means for nine agronomic traits (dry matter yield, plant height, leaf-stem ratio, harvest index, seed yield and its components). Parents, S₁, S₂, S₃, and S₄ generations of six populations of different geographical origin (3 from Egypt and 3 from southern Italy) were investigated to estimate the relative changes with increasing homozygosity and to prove the effectiveness of selfing in a breeding program. The experiment was carried out at Foggia (Italy) under field conditions for two years (1995 and 1996) adopting two cutting treatments: at fifth internode elongation (A) and flowering (B). The mean values decreased with the advancement in selfing generations in both years and cutting treatments for the most of the traits. Treatment B yielded more biomass and seed yield than treatment A in both years. Cutting treatments did not affect the adaptability of the selfed progenies of populations with different geographical origin, in fact, the Italian populations were more productive for dry matter under both cutting treatments (856.6 g m^-2 on average), whereas Egyptian populations proved superior for seed yield particularly under treatment B (62.5 g m^-2 on average). Inbreeding depression was greater for forage dry matter and seed yield (−62and −79% on average, respectively), whereas the plant height and 1000-seed weight were the least susceptible traits (−26 and −19% on average, respectively). Estimates of the parameters of the stability analysis showed that not all populations responded to inbreeding level and environment variations to the same degree. Differences were evident under treatment A, only. Development of self-fertile, relatively vigorous inbred lines of berseem clover with different degrees of homozygosity appears possible. Genotypes tolerant to selfing from Egyptian and Italian groups have been obtained by inbreeding and selection for self-fertility; they could be utilised as basis for producing new breeding activities. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effect of Seed Pre-sowing Hardening on Physiological Behaviour and Seed Yield of Berseem (Trifolium alexandrinum L.) Crop

A field experiment was conducted at Central Research Farm, Indian Grassland and Fodder Research Institute, Jhansi to study the effect of seed pre-sowing hardening on seed emergence, physiological behaviour — and seed yield of berseem ( Trifolium alexandrinum L. Var. S-99-1) crop. For this purpose, seed pre-sowing hardening were made by soaking of seeds in tap water for 24 and 36 hours separately and later dried back to their original weight or left undried. These seeds were sown at two depths (5 and 3 cm) and judged against control (no soaking). Results demonstrated that augmented effect of seed hardening on seed emergence and physiological process responsible for seed yield was recorded in descending order of harden seeds (of 24 hours soaking) > non harden seeds (of 24 hours soaking) > harden seeds (of 36 hours soaking); while non-harden seeds of 36 hours soaking adversely affect the plant growth because of leaching of sugar during excess soaking — an element for reduced seed vigour potential. Seed hardening system developed the strength of seed emergence on account of efficient catabolic process releasing high water soluble sugars needed for efficient germination process. Further this process augmented the absorption mechanism of mineral nutrients (particularly phosphorus and nitrogen with marginal variation in calcium) was quite evident at bloom stage — indicating a high metabolic activity during this period. Performance of seed hardening was effective at 5 cm deep sowing.     

Development of a New Multifoliate Strain of Berseem Clover (Tricolium alexandrinum L.) in Egypt

The aim of this work was to obtain mukifoiiare types of berseem clover with a great proportion of the leaf weight and increased plant weight. Thereby research an berseem clover over a 10 year period resulted in the transfer of the multicare gene(s) from a mutant plant of the monocut Fahl culrivar which possess such trait to the muiticut trifoliate culrivar Meskawi by crossing between them. A multicut multifoliate strain was developed after rune generations of selection.
The multsfoliate strain gave significantly higher dry forage yield than commercial cultivate Giza 10, Sakha 4, Giza 15, Helaly and Giza 6 by 22.1, 22.5, 24,8, 29.9 and 36.7%, respectively, in the first cut. On the other hand, the moltifoliate strain gave higher seasonal protein yield than cultivars, i.e. Helaly, Giza 10, and Giza 6 by 7.0,10.1, and 121 %, respectively.
The leaves/stems rario trait averaged over cuts was 18.3 % higher than for the five commercial trifoliate cultivars. Therefore, this multifoliate muiricut strain could be useful for forage especially before sowing cotton or other early summer crops. In addition to that, it could he used as a genetic marker for berseem breeders.     

A comparison of methods for hybrid seed production using self-incompatibility in swedes (Brassica napus ssp. napobrassica)

Procedures for producing seed of hybrid swedes using self-incompatibility were examined. Single-cross, double-cross and modified double-cross hybrids were compared in isolation plots using natural pollinators and in polythene tunnels using blow-flies. With good coincidence of flowering and the same flower colour, nearly 100% hybrid seed was produced by natural pollinators with the single-crosses, the double-cross and one of the two modified double-cross hybrids; the other modified double-cross hybrid produced 87%hybrid seed. With poor coincidence of flowering and different flower colours the proportion of hybrids dropped to 61%. Using different flower colours and blow-flies as pollinators in polythene tunnels, higher levels of outcrossing were produced than in isolation plots with natural pollinators; the opposite result was obtained when the same flower colour was used. This revised version was published online in July 2006 with corrections to the Cover Date.     

亚种间杂交稻协优9308的结实特性与生理基础

以比较生理学研究方法,研究亚种间杂交稻协优9308与品种间杂交稻协优63的籽粒灌浆特性.结果表明:灌浆成熟期亚种间杂交稻协优9308与品种间杂交稻协优63都有"粒间顶端优势"特性,亚种间杂交稻协优9308比品种间杂交稻协优63的"粒间顶端优势"更明显.但是,由于协优9308灌浆成熟期稻株生理活性高,支撑其劣势粒充实,优劣势粒的平均结     

7份云南野生画眉草属植物种子产量及萌发特性研究

以云南分布较为广泛的7份野生画眉草属植物材料为研究对象,以弯叶画眉草为对照,对种子产量及萌发特性进行初步研究,以确定云南野生画眉草属植物的结实性能和发芽规律.结果表明,供试材料均表现出较好的开花结实性能,种子产量以弯叶画眉草最高,达525.4 kg/hm2,黑穗画眉草次之,知风草最低;种子千粒重为弯叶画眉草＞知风草＞黑穗画眉草;种间相比较,弯叶画眉草的发芽势和发芽率均最高,分别为91.7％和93.0％,显著高于黑穗画眉草和知风草(p＜0.01);种内相比较,5份黑稳画眉草间的发芽势和发芽率差异较大(p＜0.01或p＜0.05),2份知风草间差异不显著(p＞0.05).     

杭白芍结实性状及籽油品质分析

分析杭白芍结实性状及其籽油品质,为芍药籽油专用品种培育及籽油开发利用提供理论参考。对杭白芍的结实性状相关性和籽油理化性质进行测试和分析,结果表明：（1）单心皮种子数和心皮长均与单株产量呈极显著正相关,蓇葖果数与单株产量呈显著正相关,分株数与单株产量呈显著负相关;主成分分析表明,前4个主成分累计贡献率达88.8768%。（2）籽油测试结果表明,种子含油率21.31%,油酸40.56%,亚油酸29.16%,亚麻酸22.11%,籽油不饱和脂肪酸91.83%,维生素E含量79.64 mg/100 g。因此,在选育高产品系时要重点关注单心皮种子数、心皮长和蓇葖果数等性状指标。杭白芍籽油具有较高的食用价值,可以作为一种新型的油料作物,具备深入研究推广的价值。     

苜蓿雄性不育系杂交制种产量性状分析

以回交转育得到8个苜蓿雄性不育株(系)和3个优良苜蓿品种为亲本,分别在开放授粉和人工控制下进行杂交制种试验.结果表明:切叶蜂辅助授粉方式可以有效提高苜蓿雄性不育株(系)的制种产量.综合2种授粉方式下的制种产量,其中2号不育株(系)单株种子产量最高(3.16g/株);通过苜蓿雄性不育株(系)种子产量的相关分析和回归分析,明确了每株生殖枝数对不育株(系)单株种子产量作用影响最大,其次是结实率.     

Pollination behaviour among different breeding populations of Egyptian clover

Pollination behaviour and the extent of self‐compatibility were studied in Trifolium alexandrinum, commonly known as Berseem or Egyptian clover, an important fodder legume cultivated in Egypt, the Mediterranean basin and the Indian subcontinent. Four treatments were imposed on 16 populations comprising three diploid exotic, three diploid advanced breeding, five induced tetraploid and five diploid pentafoliate lines. The different treatments were open pollination, caging, hand tripping and controlled bee visits. Compared with the open pollinated condition, reduction in seed set in different populations ranged from 12.3 to 99.2% under caged condition. Eight of 16 populations registered more than 90% reduction in seed set. Hand tripping and/or controlled bee visits improved seed set considerably in a few populations, whereas, in one population, no significant effect of these four treatments was observed. The results indicated considerable variation for self‐compatibility, together with a requirement of tripping for pollination and seed set, even in self‐compatible lines.     

The value of comparative tests of progenies from open-pollinated female asparagus plants

From seed yield determinations in an isolated seed garden the conclusion has been drawn that a male asparagus plant only pollinates those female plants which grow very close to it. The so-called open pollination of a female plant in a commercial or trial field can therefore only be carried out out by a very limited number of male plants.Comparison of the yield from selected female plants with the yield of those groups of pollinators which belong to these female plants shows that the variations in the production of spears are about equally large. From this it was concluded that the father plants have as large an effect as the mother plants on the characters of progenies of open-pollinated female plants.Therefore assessment of the genetical value of open-pollinated mother plants on the basis of a progeny test is considered to be unreliable.     

水稻籼爪交和粳爪交杂种优势的研究Ⅱ.农艺性状的杂种优势分析

研究了籼爪交和粳爪交杂种在长沙、三亚的农艺性状和干物质产量的杂种优势.在长沙的籼爪交杂种在结实率和每穗实粒数方面具有负向超亲优势,在每穗实粒数、结实率、单株粒重和理论产量方面存在负向对照优势,其余性状均为正向优势;粳爪交杂种在千粒重和结实率方面存在负向超亲优势,其余性状为正向超亲优势, 在始穗期、秆高和单     

盐逆境对耐盐水稻穗部性状及产量构成因素的影响

探明不同盐逆境水平对耐盐水稻穗部性状及产量构成因素的影响,旨在为沿海滩涂水稻种植和耐盐水稻高产育种提供科学依据.以'扬农稻1号'(V1)、'南粳5055'(V2)和'通海粳18-2'(V3)为试材,利用盐池设施设置O g/kg(S0)、1.5 g/kg(S1)、3 g/kg(S2)3个不同盐分水平,采用裂区试验,测定分...     

P2西瓜采种植株的生理性状与种子产量,质量的关系

采种植株生理性状与种子产量相关,但与种子质量无关。其中,雌花序位置与单瓜种子总重量和单瓜种子总数(r=0.48,0.60),座瓜位置与单瓜种子总数(r=0.65),座瓜叶数与单瓜种子总重量和单瓜种子总数(r=0.52,0.63),单瓜种子总数与单瓜种子总重量之间(r=0.94)呈正相关。而雌花序位置、座瓜位置、座瓜叶数和单瓜种子总数均与百粒重呈负相关(r=-0.58,-0.62,-0.56,-0.48)。但种瓜直径与种子产量之间无明显关系。     

不同传粉方式对子莲授粉效果的影响

[目的]子莲是一种基础产量比较低的植物,需要依赖传粉者的活动才能完成胚珠受精,授粉优劣是直接影响子莲产量与质量的重要因素。[方法]中华蜜蜂和意大利蜜蜂都是理想的授粉昆虫,各有其独特的生物学特性,在抗逆性、采集积极性和采集偏好性等生物学特性方面均存在不同差异。应用意蜂和中蜂为大田子莲授粉,对其采集活动方式与授粉效果进行了对比研究。[结果]1、活动方式结果表明：它们的采集行为相似,但活动方式不同,在夏季高温天气,意蜂较中蜂的采集工作时间要长,因此具有更高的授粉效益。2、授粉效果结果表明：与产量相关的子莲单粒重、接籽率;与商品性相关的莲子纵、横径4项指标,意蜂授粉组与中蜂授粉组之间差异不显著,但与自然授粉组和无虫媒授粉组之间差异显著。其中,意蜂授粉组的平均接籽率最高为87.82%,较自然授粉组和无虫媒授粉组接籽率分别提高33.27%和79.10%;自然授粉组莲子平均单粒重最大达3.68g,显著高于其他授粉类型;无虫媒授粉组较其他授粉组莲子果型最小。同时,与产量相关的子莲蓬粒总重,意蜂授粉组与其他授粉组之间,均差异显著,较中蜂授粉组、自然授粉组和无虫媒授粉组蓬粒总重分别提高25.88%、37.67%和665.50%。[结论]据此得出意蜂与中蜂具有类似的授粉效果,都能够完成授粉任务,意蜂较中蜂授粉能够获得较高的子莲产量,并显著优越于自然授粉与无虫媒授粉方式, 从而产生更高的授粉效益。