珍稀树种的种苗繁殖研究

本文对１０种珍稀树种的采种期、采种方法、种子处理、贮藏方法、育苗方法以及幼苗形态特征等进行了较为系统的介绍。     

我国结缕草种质资源结实性的初步研究

对我国65份有代表性的结缕草种质资源的种子产量及其组分包括花穗密度、单位花穗种子数以及干粒重进行了观测分析。结果表明，结缕草种质资源的种子产量及其组分存在很大的变异，其中种子产量变异幅度最大，变异系数达101％，种子产量组分的变异系数大小排序为：花穗密度＞干粒重＞单位花穗种子数。通径分析的结果表明，花穗密度对种子产量的贡献最大，其次为单位花穗种子数，最后为干粒重。多重比较结果表明，Z039、Z113、Z116、Z016以及Z103的种子产量显著高于其他种源。     

用活力指标评价几种牧草的种批质量和田间出苗率

采用一系列试验室和田间试验，以探讨催腐、电导、发芽势、发芽指数和幼苗根长等活力指标用于评价牧草种批质量和田间出苗率的适用性。供试牧草种为紫花苜蓿、光叶紫花苕、苏丹草和老芒麦。试验结果表明，与标准发芽率相比较，电导和催腐法可更为有效地预测2种豆科牧草种子的出苗率和划分光叶紫花苕的种批质量；发芽势和发芽指数可更准确地预测苏丹草的出苗率；而发芽指数可更灵敏地划分老芒麦的种批质量。其他活力方法在评价其他质量指标方面未显示出优越性。讨论了影响活力测定的因素。     

Characteristics of Seedling Raising and Mechanized Transplanting of Hybrid Rice with a Low Seeding Rate by Precise Seeding Method

【Objective】 The purpose of the study is to ascertain the effect of precise hill-sowing and drill-sowing methods on seedling raising and the characteristics of mechanized transplanting of hybrid rice with a low seed sowing rate below 70 g, and to further break the current technical bottleneck in mechanized transplanting process of hybrid rice. 【Method】 In this study, Zhongzheyou 1 and Yongyou 1540 were mechanically hill-sowed and drill-sowed in standard seedling raising trays with mechanized broadcasting as the control. The hill-sowing specification was 16×34 hill, and 16 drills were set in longitudinal direction for drill sowing. The seed sowing rates were 5 seeds, 3 seeds, and 2 seeds per hill for hill sowing, and the same seed rates were set in drill sowing. The effects of different sowing methods on the growth of seedlings and their mechanical transplanting characteristics were investigated. 【Results】 1) Sowing methods presented no significant effect on seedling percentage with a reduction in seeding rate. 2) A reduction in seeding rate improved rice seedling consistency, especially in hill sowing and drill sowing as compared with broadcasting. 3) In comparison with seed broadcasting, under hill seeding and drill seeding, seedling roots were more entwined as seedling mats. Under hill-sowing and drill sowing, Zhongzheyou 1 and Yongyou 1540 had 75.4% and 81.0% higher intertwining force than that of broadcasting, respectively. Precise hill- and drill-sowing generated effective seedling blanket without significant difference between the two treatments, while broadcast sowing did not. 4) Hill sowing and drill sowing significantly reduced the missed hill percent of machine transplanting. The missed hill percent of Zhongzheyou 1 and Yongyou 1540 under hill sowing and drill sowing were 76.3% and 74.6% lower than that of broadcast sowing in average, respectively. The missed hill percent for hill-seeding and drill-seeding with 3 seeds per hill was below 1%, 10% lower than that of broadcast sowing. 5) The uniformity of machine-transplanted seedling under hill sowing and drill sowing were better than that of broadcast sowing. And the proportion of the treatments with expected seedling-catching number in mechanized transplanting (2 to 5 seedlings with 5 seeds per hill, 1 to 3 seedlings with 3 seeds per hill and 1 to 2 seedlings with 2 seeds per hill) for the two cultivars were all above 80% in hill-sowing and drill-sowing in combination with machine transplanting, and the seedling uniformity of machine-transplanted Zhongzheyou 1 and Yongyou 1540 was 121.2% and 67.0% higher than that under broadcast sowing. Meanwhile hill sowing had a better result than drill sowing. 【Conclusion】 Precision hill seeding and drill seeding provide an alternative measure to current problems such as large amount of seeds, high missed hill percent and uneven seedling taking in the process of machine transplanting of rice.     

钴离子抑制种子引发对绿豆抗旱性的诱导过程

以陕西农家品种绿豆为材料，研究了钴对种子萌发，种子引发及幼苗生长的影响，结果表：在０．２－１．０ｍｍｏｌｅＬ＾－１浓度范围内，钴离子能够延迟缓豆种子萌发，抑制幼苗生长，这种效应随钴浓度的增加而加大，种子引发能够加快种子萌发，促进幼苗生长，提高细胞膜稳定性，植物对渗透胁迫的适应，在引发过程中，加入２ｍｍｏｌｅＬ＾－１ＣｏＣｌ２能够抑制种子引发对植物抗旱性的诱导作用，但不影响种了萌发，进一步实验表明，     

Changes in starch,oil, protein and amino acids in developing seeds of okra (Abelmoschus esculentus L. Moench)

The okra seeds of variety Pusa sawani were analysed for protein, non-protein nitrogen, total free amino acids, lysine, and tryptophan from the 7th day to the 42nd day after flowering. Starch, total sugars and oil percent were also estimated in these seeds. During the early stages of maturation, the soluble components (non-protein nitrogen, free amino acids and total sugars) were found in higher quantities than in the later stages. Protein, oil and starch contents increased gradually from day 7 to day 42. The rate of accumulation of oil was found to be at the highest level between 21–28 days after flowering, while the rate of protein deposition was greatest between days 35–42. Inditiation of seed maturation seems to start 21 days after flowering in okra seeds.     

Effect of Date of Planting, Genotype and Source of Seed on Disease Incidence, Yield, and Agronomic Performance of Soybean

Four soybean genotypes chosen from four seed sources were planted in a factorial arrangement on four dates in a split-plot design at the Alabama A & M Experimental Station on a Decatur silt clay loam soil. The highest vigor index was recorded from seeds harvested from the 4th date of planting. These seeds had the lowest level of Diaporthe phaseolorum var. caulivora infection, indicating that vigor index, as a measurement of seed quality, was negatively correlated with the level of infection by soybean stem canker pathogen. Seed yield was highest at the 2nd date of planting and lowest at the 4th date of planting. Tracy-M and Bedford confirmed previous reports on their resistance and susceptibility, respectively, to soybean stem canker. All the genotypes performed their best at the 2nd date of planting. Source of seeds appeared to have little effect on the performance of the plant in the field.     

盐分浓度对星星草种子萌发的影响

星星草（Ｐｕｃｃｉｎｅｌｌｉａｔｅｎｕｉｆｌｏｒａ）种子经不同浓度ＮａＣｌ溶液处理结果表明；与对照相比，低于０．６ｇ／１００ｍｌ的盐浓度对种子萌发有促进作用；介于０．７ｇ／１００ｍｌ—３．６ｇ／１００ｍｌ间，种子的萌发势和累积发芽率显著下降，但尚不影响其萌发潜势，解除盐分限制后，还可正常萌发；高于３．７ｇ／１００ｍｌ后，不仅抑制种子萌发，并对其萌发潜势有显著影响。     

四合木种子特性的测定研究

本文就蒺藜科的四合木种子进行了千粒重，吸水增重率，发芽率，生活力，活力五项测定，并分析了测定结果与方法，得出了很有价值的结论。