离体条件下水稻种衣剂对串珠镰刀菌生长及形态毒理影响

 检测了黑龙江水稻主产区4个当地主栽品种的种子内部镰刀菌寄藏情况,测定了20%克福甲和20%克多甲种衣剂对种子带菌消毒处理效果及对水稻串珠镰刀菌(Fusarium moniliforme)的抑菌作用和联合毒力,并借助扫描电镜观察了上述2种混配种衣剂对串珠镰刀菌的形态毒理影响。结果表明,种子内部镰刀菌的分离频率高达56.7%~96.0%,其中串珠镰刀菌的分离频率为32.6%~48.2%,2种种衣剂对带菌种子具有显著的消毒处理效果。20%克福甲和20%克多甲种衣剂对镰刀菌F.moniliforme的毒力指数分别为457.11和802.04,增效倍数分别为6.53和0.13。20%克多甲种衣剂(多菌灵:甲基立枯磷为5:5,W/W)对串珠镰刀菌的抑菌作用优于20%克福甲种衣剂(福美双:甲基立枯磷为8:6,W/W),增效作用低于20%克福甲种衣剂。电镜观察表明,种衣剂低浓度至高浓度处理下均可引起串珠镰刀菌菌丝不同程度的异常生长,表现为主菌丝局部膨大或形成菌丝束,菌丝顶端异常膨大、缢缩或形成穗状和花絮状分枝。     

玉米疯顶病种子传播研究

连续3a对不同来源的玉米种子,利用显微镜镜检和试种观察植株发病显症的方法,检测其携带玉米疯顶病病菌状况。结果表明,病株病穗籽粒、病株健穗籽粒、病田健株籽粒都有较高的带菌率。因此,病菌随种子调运远距离传播是造成各地病害突发的主要原因。     

节水灌溉对葡萄及葡萄酒质量的影响

 研究了不同灌溉方法对葡萄生长发育、浆果品质和葡萄酒质量的影响。结果表明, 节水灌溉显著改善了土壤结构, 增加了深层土壤的根系密度; 提高了果汁糖含量, 降低了酸含量和全盐含量, 改善了pH 值; 提高了葡萄酒的感官质量, 酒体丰满, 香气浓郁, 滋味更好; 年灌溉用水量3825 ~ 4800m3# hm^-2, 比常规灌溉节水36%。     

6-BA在葡萄植株体内的运转和分配

以葡萄为试材,研究了葡萄根、茎、叶、果等器官对6-苄基腺嘌呤(6-BA)的吸收及它在植株内的运转和分配。结果表明,对1年生葡萄幼苗茎部引入或叶片涂抹6-BA,1h后,在植株所有部位都有分布,其中以茎尖和根部浓度较高,表现为快速、非极性的运输特性。茎部引入5d之内,植株根内6-BA呈持续升高趋势,茎尖内6-BA虽然有波动,但是最后仍达到最大;而叶片涂抹则在涂抹后5h时,全株各部位6-BA浓度达到最大,5d后,除引入叶片外,其它部位几乎测不到6-BA。盛花后30d,果穗浸蘸和穗轴引入6-BA,2h后,果皮、果肉、种子中6-BA浓度达到高峰,以后逐渐下降,果穗浸蘸30d后,果实各部位均已测不到6-BA,穗轴引入30d后,果皮和果肉内仍能测到6-BA,但种子内已测不到。     

极早熟葡萄新品种‘90- 1’

 ‘90- 1’是从‘乍娜’的芽变中选出的葡萄新品种。该品种除保持母本的优质、丰产、适合保护地栽培等优良性状外, 其最突出的特点是极早熟, 果实6 月下旬成熟, 果实发育期仅35 d。     

Variation of Parthenium hysterophorus in response to soil quality: implications for invasiveness

Summary The performance of Parthenium hysterophorus , native to the tropical Americas and invasive to several countries, was evaluated for response to soil quality. Phenological (six stages) and quantitative growth variables [relative growth rates in height (R_h) and diameter (R_d)] were measured every fortnight. Based on harvest data, the variables, root:shoot (R:S) ratio, specific leaf area (SLA), relative growth rate in biomass (R_w), net assimilation rate (NAR) and dry matter allocation to plant components, were determined. High clay content in soils prolonged the rosette stage, enhanced R_h and R_d and hampered root growth, but promoted biomass allocation to shoots. The extreme degree of plant mortality was observed, with only 33.3% individuals surviving to reproduce in the soils with highest clay contents. This appears to be one of the most important findings that certainly has a major bearing on the range of adaptation of the weed. Seed mass declined whereas seed production increased in relatively coarser soils with the exception of nearly pure sand. In soils rich in clay, plants produced a smaller number of larger seeds. These data suggest that variation in fundamental functional traits would enable P. hysterophorus to adjust to a variety of habitat conditions.     

Leaf, floret and seed infection of wheat by Pyrenophora semeniperda

Infection processes of Pyrenophora semeniperda on seedling and adult wheat leaves and wheat ears were investigated. Almost 100% germination of conidia occurred on seedling leaves, compared with 20–30% on adult leaves. Appressoria formed over the anticlinal epidermal cell walls and haloes always accompanied infection. Sometimes papillae formed within the leaves as a resistance mechanism. Infection hyphae ramified through the intercellular spaces of the mesophyll resulting in cellular disruption. The infection processes on floral tissues were similar to those observed on leaves; however, no infection occurred on anther, stigmatic or stylar tissues. Infection of ovarian tissue occurred both with and without appressoria formation. Hyphae grew mainly in the epidermal layers and appeared unable to breach the integumental layer as no growth was observed in endosperm or embryo tissues. The optimum dew period temperature for conidial germination was 23·6°C, compared with 19·9°C for lesion development, 20·4°C for the production of infection structures on seedling leaves and 23·7°C for floret infection. Leaf disease development occurred in a logistic manner in response to dew period, with maximum infection observed after 21 h compared with > 48 h in seeds. An initial dark phase during the dew period was necessary for infection and temperature after the dew period had an effect, with significantly more numerous and larger lesions being formed at 15°C compared with 30°C. Seedling leaves were found to be more susceptible than older leaves, under both field and controlled environment conditions. Infection of wheat seeds following inoculation of ears, or after harvest burial of inoculated disease-free seeds, was demonstrated. In the latter, 3-week-old seedlings were slightly stunted, whereas older plants were unaffected. The apparent unimportance of this plant pathogen as a cause of leaf disease in relation to its poor adaptation to dew periods and dew period temperature is discussed, along with the importance of its seed borne characteristics.     

两系稻制种穗期病害发生较重的原因及防治措施

调查分析稻粒黑粉病、穗颈稻瘟等两系杂交稻制种穗期主要病害的发生原因,提出了清除菌源、轮换制种、健身栽培、对口药剂防治等防治措施。     

The effect of populations of Xanthomonas campestris pv. phaseoli in bean reproductive tissues on seed infection of resistant and susceptible bean genotypes

Surface and internal populations of Xanthomonas campestris pv. phaseoli, causal agent of common bacterial blight of bean, on and in flower buds, blossoms and pods of seven bean (Phaseolus vulgaris) genotypes were studied. Bean plants were grown in the field and artificially inoculated at the seedling stage (18 days old). The pathogen was recovered in high numbers from flower buds, blossoms, pods and seed of both resistant and susceptible bean genotypes. Significant differences (P = 0.05) in population levels of X. c. pv. phaseoli between stages of reproductive tissue development were observed. Infected seed from resistant bean genotypes had no visible symptoms. Such seed may play an important role in the epidemiology of common bacterial blight because they are difficult to detect and may occur at low frequency in seed lots, as was the case in the current study.