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.     

Effect of Phenological Stages on Plant Dry Matter Partitioning and Seed Production in Berseem (Trifolium alexandrinum L.)

Berseem clover ( Trifolium alexandrinum L.) is an annual forage crop widely grown in Mediterranean environments. Dry matter partitioning in the leaf, stem and root and seed production of three populations of Egyptian as well as Italian origin were evaluated under four cutting regimes. The cutting treatments were applied to the plants at different stages of plant development: at the fourth (A) and eighth nodes elongation (B), at early flowering (C) and physiological maturity of seeds (D), After herbage, harvest plants were utilized for seed yield and evaluation of its seed yield components. Higher dry matter and seed yield was obtained in treatments D and B, respectively. In the other treatments, dry matter content was lower than in treatment D and related to the phenological development of the plant. Dry matter content in the root was higher when the cut was applied at early flowering. Cutting regimes influenced plant mortality, with the number of dead plants increasing from the cut applied in early (A) to that in the final treatment (D). Cuts applied at early stage of development depleted root reserves causing plant death. This peculiarity could be a tool for selecting populations with higher persistence and with a more tolerant physiological response to stress imposed by cuts. The populations of Egyptian origin, in comparison with the Italian ones, were more productive in dry matter in the early stage of growth and in all treatments were higher in seed weight.     

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.     

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.     

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.     

土壤水分对谷子(粟)结实的影响及其生理效应

土壤水分对谷子结实的影响主要在结实阶段.土壤水分过少或过多,都能显著降低结实率、成粒数和产量.这一时期以保持土壤毛管持水量的70%左右对结实最为有利.供水不足,首先影响根系活性和体内水分状况,从而影响体内外气体交换,降低光合速率和呼吸强度,同时影响细胞膜透性,导致体内物质代谢过程改变,降低有机物质的积累,造成穗部营养贫乏,形成秕谷.土壤水分过多,通气不良,影响根系活性,降低伤流量,抑制体内代谢过程及物质运转,造成穗部营养不足,形成秕谷.     

金钗石斛传粉生物学和种子萌发特性研究

选用金钗石斛(Dendrobium nobileL ind l)生长旺盛的大花朵进行人工授粉繁育,研究结果表明:授粉后经过6~8个月发育成熟,其蒴果大、种子数量多;从结实率可看出,开花第1天发芽力最强,结实率最高。开花后9天花粉块仍可应用。雌花(母本)最好的授粉时间是在开花后1~6天,10天以后结实效果差。同时采集3年的金钗石斛种子分别播种在KC和VW培养基上,采用固体、半固体、液体3种物理状态培养方式作种子发芽对比试验,最终研究结果为:种子萌发率以当年播种在KC培养基(液体)上的最高,可达89%以上,说明金钗石斛种子没有休眠特性。     

不同播期和品种小麦小花结实的粒位差异

确定小麦不同小穗位和小花位发育与结实特性是实现大穗多粒的重要前提，本文通过对冬，春性小麦品种分期播种试验得出，较高的小穗结实力是增加穗粒数的重要因素，不同播期，品种之间，小穗粒重和粒数呈现相同的变化趋势，中部以及基部小穗粒重与穗粒重之间呈高度正相关，体现环境差异的播期效应以对中部小穗发育的影响为主，而冬，春性品种的基因型差异可反映在各个小穗位上，第2小花粒的子粒发育状况反映整个小穗的生产能力，结果表明，促进中部优势小穗（第5－15小穗）结实和第1－3小花位子粒发育是提高小花结实率和穗粒重的关键。     

Genetic Variability, Genotypic and Phenotypic Correlations and Path-Coefficient Analysis in Egyptian Clover (Trifolium alexandrinum L.)

Fifty-six accessions of multi-cut Egyptian clover were compared at four experiments under different environmental conditions; i.e. location and season. Considerable variation existed for all the characters studied. The genetic variance exceeded the environmental variance for all the studied traits. Heritability was high for all characters studied. The expected genetic advance from selection of the superior 10.7% of the accessions as calculated from the combined data reached to 16.10, 17.50, 5.20, 20.60, 3.52 and 21.00 for mean plant height, seasonal fresh forage yield, mean dry matter percentage, seasonal dry forage yield, mean protein percentage, and seasonal protein yield, respectively. Both phenotypic and genotypic correlations among traits showed that mean plant height was positively correlated with each of seasonal fresh forage yield, seasonal dry forage yield, mean dry matter percentage and seasonal protein yield, but negatively correlated with mean protein percentage. Negative correlation were also found between mean protein percentage with seasonal fresh and dry forage yield.
Over all experiments, pat-coefficient analysis revealed that seasonal fresh forage yield had the highest positive direct effect on seasonal protein yield (0.841), followed by mean dry matter percentage (0.461). The mean protein percentage showed the minimum direct (0.172) and indirect influence on seasonal protein yield.     

Ultrastructure of Seed Coat Development in the Natural Tetraploid Trifolium pratense L.

Seed coat development in the natural tetraploid Trifolium pratense L. was studied by electron microscopy. The mature seed coat derived from the outer integument is composed of three layers of cells. The cells of the outer epidermis divide anticlinally and undergo radial elongation to form a macrosclereid layer. The cells are characterized by thin walls, the presence of amyloplasts, and numerous vacuoles which are completely or incompletely filled with tannin. The outer tangential walls are thickened at an early stage. An electron-translucent cap develops in the outer tangential walls of the macrosclereid cells at the globular embryo stage. Osteosclereid cells are highly vacuolate with densely staining cytoplasm. Gradually, extensive intercellular spaces are formed. The parenchyma cells are small and have prominent intercellular air spaces. Maturation eventually leads to the disappearance of cytoplasm in all cells, and the compression of the cells of the parenchyma layer.     

戴云山自然保护区种子植物传粉模式研究

以戴云山国家级自然保护区种子植物名录为研究对象,基于APWeb和文献资料统计种子植物科的传粉模式,研究了戴云山保护区种子植物的主要传粉模式及其传粉模式的祖先状态。结果表明:戴云山保护区种子植物中动物参与传粉有144科,占总科数87.27%;完全利用非生物模式传粉占总科数12.12%;单一传粉模式以动物传粉的科数最多(124科),其次为风媒传粉(14科),水媒传粉最少(4科)。混合传粉模式中,动物和风媒传粉的科数最多。动物传粉模式在戴云山保护区种子植物传粉中占据重要地位。戴云山保护区种子植物科中共有9个原始类群,单一动物传粉8科,动物和风媒混合传粉有1科,表明动物传粉在植物原始类群进化中占据主要地位,可能是现存戴云山被子植物传粉模式中的祖先状态。研究结果旨在为戴云山种子植物发育与演变提供理论依据。     

光照条件及无机营养对谷子结实的影响

光照条件及无机营养是影响谷子(粟)结实的重要生态因子.从抽穗到抽穗后20天遮光处理对谷子结实有严重影响.用1层、2层和3层纱布遮光,秕谷率分别增高6.18%、25.67%和37.56%,成粒数分别减少33.44%、43.56%和63.08%.遮光程度和秕谷率、成粒数的相关系数分别为0.98和-0.98.氮素营养水平与颖花数、秕谷率的相关系数分别为0.9699和-0.9798.氮素营养在谷子抽穗前18天和抽穗后20天对结实影响最大,此时提高氮素营养水平,秕谷率比对照降低7.22%和9.87%.氮素营养对结实的影响同时也受降水的制约.磷、钾、硼等元素对谷子结实也有明显的影响.本文从生理上分析了光照条件和无机营养对谷子结实的影响.     

华北驼绒藜花粉萌发特性及不同授粉方式对其结实率的影响

为寻找华北驼绒藜结实率低、群落退化的原因,在栽培条件下对其花粉生活力、寿命、柱头萌发率与结实率的关系进行了相关性研究。采用同株、异株、自然授粉处理华北驼绒藜,同株授粉结实率(81.53%)显著低于异株授粉(88.6%)和自然授粉(92.6%)的结实率;采用TTC法对华北驼绒藜花粉寿命和生活力的研究结果表明,其平均寿命为6d,最佳授粉时间为1~3d,生活力达95%左右,不存在花粉败育和短命的问题,即不存在小孢子发育障碍。3种授粉方式处理后,采用荧光显微镜观察华北驼绒藜花粉在柱头上的萌发率,萌发高峰集中在授粉后3~4h,萌发率达90%以上,三者不存在显著差异,即华北驼绒藜不存在花粉与柱头的识别障碍。结实率与花粉在柱头萌发率的相关分析结果表明,二者不存在相关性。研究初步认为,同株授粉产生结实率低的原因可能发生在授精或胚胎发育过程,有待进一步研究。目前,华北驼绒藜野生群落严重退化,植被密度减少,可能存在大量自株授粉是造成群落退化的原因之一。     

固体介质辅助授粉对烟草坐果和种子活力的影响

采用云烟87纯花粉与膨润土、面粉、GTG粉、脱脂奶粉、蜂花粉、可溶性淀粉和滑石粉按体积比2∶1、1∶1、1∶2及1∶3比例均匀混合制备成固体介质花粉,以纯花粉为对照,研究介质花粉对云烟87的坐果和种子活力的影响。结果表明:在不同的固体介质中,可溶性淀粉易与纯花粉混合。按2∶1比例制备成的可溶性淀粉介质花粉,授粉后着粉情况好,每株烟的平均坐果率为90.4%,平均每蒴果种子数为3 003.9粒,与对照比无显著差异。收获后种子的发芽势和发芽率分别达90.3%和93.3%,种子活力与对照比无显著差异。可溶性淀粉介质花粉可应用于烟草种子生产,能达到节约纯花粉用量,降低生产成本的目的。     

油菜(B.napus L.)硼素营养与结实性的研究

硼营养不足,油菜植株各器官含硼量均下降,下降幅度因器官而异,而以花器官下降幅度最大。缺硼时,花器发育异常,雄蕊在解剖生理上的异常现象尤为突出,严重时花粉败育,花蕾脱落,甚至出现颗粒无收的现象。花粉败育表现为花粉囊空瘪,核质解体,无孢原组织分化,绒毡层发育异常,小孢子原生质团溢出药壁外等现象。硼营养不足降低了花药     

Prolonging Seed Viability in Groundnut (Arachis hypogaea L.) with Calcium Chloride

Groundnut pods stored in gunny bags, polythene lined gunny bags, polythene lined gunny bags with fused CaCl₂, mud pots, and bamboo baskets showed significant differences in germination and vigour. The increased viability of pods in polythene lined gunny bag with fused CaCl₂ is attributed to low moisture content and high dehydrogenase activity. The present study showed that the viability of groundnut pods could be enhanced using desiccant like fused Calcium Chloride.     

关于提高大豆杂交结实率的研究

研究了5个母本、10个父本、11个杂交日期、59个杂交时间对大豆杂交结实率的影响。结果表明,不同母本对杂交结实率影响显著,J4032、齐黄26作母本容易获得杂种后代;不同父本对杂交结实率影响极显著,Avery、G3005作父本容易获得杂种后代;不同杂交日期对杂交结实率影响极显著;不同时间杂交对杂交结实率影响不显著。影响大豆杂交结实率的因素多样而且复杂,需要后续更深入研究。     

陆地棉种子物理性状QTL定位

定位棉花种子性状的基因对揭示棉花种子性状的遗传规律,以及明确棉花种子、产量、纤维品质等性状间的遗传关系具有重要意义。以(渝棉1号×T586) F_2:7重组近交系群体构建的遗传连锁图谱,在鉴定270个家系3个环境种子物理性状的基础上,利用MQM作图方法,共检测到34个种子物理性状QTL,包括9个种子重(qSW)、5个短绒重(qFW)、3个短绒率(qFP)、8个种仁重(qKW)、6个种子壳重(qHW)和3个种仁率(qKP)QTL,它们可解释4.6%~80.1%的性状表型变异。9个QTL在2个或3个环境中被检测到,其中包括第12染色体显性光子位点的短绒重与短绒率QTL,以及另外7个微效应QTL。34个QTL分布于15条染色体,其中A染色体组20个,D染色体组14个。有12个染色体区段分布有2个或2个以上的QTL,而且同一染色体区域同一亲本所具有的不同性状QTL的方向大多数与性状表型相关系数的正负一致。     

Effect of Boron on Seed Yield in Lucerne (Medicago sativa L.)

The present study aimed at studying the effect of boron on pollen characteristics, translocation of water soluble sugars and its importance as a specific nutrient for seed production in lucerne. Aquous solutions of borax (0, 2500, 5000, 7500, 10 000 and 20 000 ppm) were sprayed at flowering stage. After 20 days, the fresh flowers were collected from the plants of all the treatments separately. The pollen was dusted on glass slides containing Muntzing's mixture for staining. After 6 hours, the data on pollen size, stainability and germination were recorded in 10 randomly selected microscopic fields. The estimation of water soluble sugars and boron content in flowers was done by standard methods. Data on grains per pod, grains per inflorescence and 1000 seed weight were recorded at seed maturity. With increasing rates of applied B, pollen germination, water soluble sugars, boron content and number of seeds per pod and per inflorescence increased but pollen fertility decreased. The pollen size and 1000 seed weight was not affected by boron concentrations. The results indicate that boron plays a definite role in increasing the seed yields through stimulating the physiological processes during reproductive phase.