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。     

Effect of Some Weed Control Treatments on Sesame (Sesamum indicum L.) and Associated Weeds

Two field experiments were carried out during 1984 and 1985 seasons at the Farm of Shandaweel Agric. Res. Station, A. R. C, Ministry of Agric. (Egypt), to study the effect of five herbicides applied as a single or in tank mixtures as well as hoeing treatment on sesame plants and dominated annual weeds under Upper Egypt growing conditions. The herbicides alachlor at 2.304, pendimethalin at 2.040, linuron at 1.200, diuron at 0.960 and prometryn at 1.920 kg a.i./ha were applied preemergence as a single herbicides, as well as alachlor and pendimethalin combined with linuron, diuron or prometryn at the same rates. Two checks were included, one was left without weed removal, while the other was hand-hoed.
Pendimethalin at 2.040 applied alone or in mixtures with linuron at 1.200 or with diuron at 0.960 kg a.i./ha gave the best grass weed control, while excellent effectiveness against annual broad-leaves was obtained by linuron at 1,200 and diuron at 0.960 kg a.i./ha alone or in mixtures with pendimethalin at 2.040 kg a.i./ha. Whereas, pendimithalin at 2.040 applied alone or in tank mixtures with linuron at 1.200 or with diuron at 0.960 kg a.i./ha gave the best control for total annual weeds and higher seed yield of sesame as well as other yield contributing characters.     

Regional and varietal differences in the risk of wheat seed infection by fungal species associated with fusarium head blight in Italy

The incidence of seed infection by fungal species pertinent to the fusarium head blight complex was monitored from 1999 to 2002 in two soft and three durum wheat cultivars grown across the northern, central and southern production zones of Italy, in order to characterize the species composition at the seed level. The main species recovered were Fusarium graminearum, F. poae and Microdochium nivale. There was a marked influence of production zone on seed infection incidence for both durum and soft wheat cultivars, with incidence of infection generally decreasing from the northern to the southern zone. Incidence of seed infection by different species of Fusarium was twice to four times higher in durum compared with the soft wheat cultivars in the study. There were no significant differences in terms of seed infection incidence between the two soft wheat cultivars, but the durum cultivars differed in their levels of seed infection for some of the pathogens. The results demonstrated that the durum cultivars were more at risk of seed infection by pathogens associated with fusarium head blight, and that wheat grown in northern Italy is at higher risk of seed infection by these species.     

Unsaturated fatty acids from zoospores of <Emphasis Type="Italic">Sclerospora graminicola</Emphasis> induce resistance in pearl millet

Downy mildew of pearl millet, caused by Sclerospora graminicola, is a devastating disease, resulting in high economic losses in the semi-arid regions of the world. Recently, induction of host plant resistance using biotic and abiotic inducers are included among disease management practices as an eco-friendly approach. Unsaturated fatty acids are considered as a new generation of plant disease resistance inducers. In the present study, six unsaturated fatty acids, viz. docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), arachidonic acid (AA), linolenic acid, linoleic acid and oleic acid, all originally detected in the zoospores of S. graminicola,were applied to seeds of susceptible cultivars of pearl millet to examine their ability to protect against downy mildew under greenhouse and field conditions. In greenhouse experiments, EPA and AA induced a maximum of 78.6% and 76.5% protection, whereas linoleic acid, DHA and linolenic acid provided up to 66.3%, 61.2% and 24.5% protection, respectively. Oleic acid was not effective in protecting pearl millet (only 5.1% protection). A time interval of four days between treatment of seeds and challenge inoculation was required to obtain optimum protection. Plants raised from treated seeds and challenge inoculated at the tillering and inflorescence stages showed enhanced resistance, resulting in higher grain yield compared to untreated plants of the same cultivar. Chitinase activity was found to be higher in susceptible seedlings of pearl millet after treatment with the fatty acids and pathogen inoculation than in seedlings only inoculated with the pathogen. This indicates that host defence responses are activated and thus that induced resistance is involved in the protection observed. The role of unsaturated fatty acids as activators of resistance against downy mildew in pearl millet is discussed.     

去毒桐籽粕饲用价值的探讨

桐籽粕含有多种醇、二萜脂等有毒物质,因而长期以来只能用于肥料。桐籽粕中含代谢能5.46MJ/kg,粗蛋白质约36.13%,赖氨酸1.43%及较多的铁。小白鼠、肉用仔鸡饲养试验及屠宰测定试验表明:在肉用仔鸡前期日粮中加入5%～8%的桐籽粕,虽然略逊于优质蛋白质饲料,但作为中、低档蛋白质饲料资源,仍具有开发价值。     

青皮种子主要储藏条件的研究Ⅰ.种子含水量与测控

水分是影响青皮(Vatica astrotricha Hance)种子活力最关键的内在因素,其中种胚含水量是决定因素。用含水量27—29％椰糠控制种胚含水量在50—52％,也就是控制种子含水量在30—36％,维持种子一定的呼吸强度(32℃下测定为50—60 O_2μl/g·h),种子活力保持最高,能延长寿命。找出了储藏中种子安全含水量的最佳点,此点处于安全含水量下限的内缘,可利用种子本身果翅与种子或大小种子之间含水量的内在关系来测定。这种测定方法准确、快速又简便。可考虑作为确定“顽拗型”种子安全含水量下限的新捷径。