壮芽灵对烤烟种子的处理效应

对云烟85、K326和红花大金元3个品种进行不同成熟期种子活力测定及壮芽灵浸种处理。结果表明：完熟期的种子活力高于褐熟期和枯熟期；壮芽灵处理种子中，以稀释1000倍，浸种24小时的效果较好，可提高中、低等活力水平的烤烟种子的活力，而对高活力烤烟种子则有轻微的抑制作用。本法对提高中、低等活力水平的烤烟具有明显作用。     

甘蓝型黄籽双低杂交油菜新品种油研九号恢复系5862R的选育

以优良的甘蓝型油菜黑籽双低品系6003和黄籽双低高油分品系408作为基础材料，采用杂交有种程序，经过5年8代（含杂交当代）的连续定向选择，育成了黄籽频率达91.6%-96.2%。含油量46.7%-49.3%，芥酸0.68%-0.14%。硫甙24.6-39.14μmol/g,丰产性与中双4号相当的甘蓝型黄籽双低新品系5862R，并被用作恢复系组配成功一个甘蓝型黄籽双低杂交油菜新品种油研九号，于1998年通过贵州省审定，至2001年秋在长江流域各省已累计示范推广面积达4万公顷左右。     

Electrophoretic Analysis of Eleven Isozyme Systems and their Possible Use as Biochemical Markers in Breeding of Chicory (Cichorium intybus L.)

Polymorphism and ontogeny of 11 chicory (Cichorium intybus L.) enzymatic systems have been analyzed by native polyacrylamide gel electrophoresis, namely: leucine aminopeptidase, phosphoglucomutase, shikimate dehydrogenase, glutamate oxaloacetate transaminase, superoxide dismutase, isocitrate dehydrogenase, esterase, phosphorylase, glucose-6-phosphate dehydrogenase, 6-phos-phogluconate dehydrogenase and glucose phosphate isomerase. The use of these systems as biochemical markers is discussed.     

Sensitivity to Drought Stress of Three Soybean Cultivars During Different Growth Stages

Three soybean ( Glycine max L.) culivars, Lee-74, Wright , and Ra 401 , were subjected to 100 % (control), 75 %, and 50 % of field capacity during vegetative (VI), flowering (R2), and pod-filling (R4) stages in greenhouse and field studies. Stress applied at R2 significantly reduced the yield in the greenhouse, while in the field, the maximum reduction was observed when the plants were subjected to stress at R4. Stress during VI reduced the yield components less than stress applied during R2 or R4 stages in both studies. The pod number and seed weight were the yield components most affected by drought stress, and the number of seeds per pod the least affected. Yield stress index was significantly correlated with the yield and its components. The reproductive stage was clearly more sensitive to drought than the vegetative stage. The cultivar Lee 74 had the highest yield and the second highest yield stress index whereas the cultivar Ra 401 had the lowest yield.     

黄粉虫粪不同用量对制种黄瓜幼苗质量的影响

研究了营养土中不同黄粉虫粪搀入量对马坊营旱黄瓜幼苗生长的影响，结果表明：用黄粉虫粪与营养土按1：(160-320)(体积比)混配的基质进行黄瓜育苗，能促进幼苗生长，显著提高幼苗简单指标、相对指标和复合指标的值。     

久保桃湿冷贮藏过程中生理生化指标的变化

研究了久保桃在温度1℃±1℃,相对湿度(RH)90%的湿冷保鲜贮藏条件下的几种生理生化指标的变化。试验结果表明,复合保鲜剂在湿冷贮藏条件下能有效地保持久保桃果实的采后品质,可明显抑制桃果实的可溶性固形物含量的增加和果实硬度的下降,降低果实褐变率,从而延缓大桃的成熟。     

多效唑处理对直播油菜机械收获相关性状及产量的影响

以阳光2009与沣油520为材料,于封行期及蕾薹初期喷施不同浓度多效唑,测定倒伏、角果抗裂性及产量相关指标,研究多效唑对油菜产量和机械收获相关性状的影响,为高产及机械收获条件下油菜的多效唑调控提供技术支撑及理论依据。结果表明,不同时期多效唑处理均显著提高2个油菜品种的抗倒性、抗裂角性及产量,蕾薹初期喷施300 mg L–1多效唑后油菜抗倒与抗裂角指数增量大,封行期喷施150 mg L–1多效唑则后产量的增量大。多效唑处理降低每角果粒数,但增加油菜品种的单株角果数及千粒重,故而增加产量;且可通过增加油菜根颈粗、鲜重根冠比及抗折力降低株高和倒伏指数,提高油菜抗根倒与抗茎倒能力;通过增加角果含水量、延缓角果成熟度、增加角果皮干重提高油菜角果抗裂性。本研究认为封行期喷施150 mg L–1的多效唑是最佳喷施时期与喷施浓度,既可显著增强易倒伏而减产油菜田块的抗倒与抗裂角能力,最大幅度地提高产量,又可满足油菜机械化生产模式所需的高产、抗倒及抗裂角要求。     

Assessment of partial resistance to powdery mildew in Chinese wheat varieties

Field trials in two cropping seasons and two locations in central China were conducted on 60 Chinese autumn‐sown wheat varieties to assess their partial resistance to powdery mildew. Mean levels of disease severity ranged from close to 0 to more than 90%. The method of inoculation and the location in which trials were conducted affected the relative performance of the varieties, but these effects were much smaller than the main effect of variety. The area under the disease progress curve was highly correlated with final disease severity, but both were poorly correlated with apparent infection rate. Disease severity was regressed against frequencies of virulence in the Blumeria graminis (syn. Erysiphe graminis) f sp. tritici populations in the trial plots. A vertical distance (D) from the mean mildew severity to the fitted line was calculated for each variety and was used to quantify partial resistance. Five of the 60 varieties, ‘Hx8541’, ‘E28547’, ‘Chuan1066’, ‘Zhe88pin6’ and ‘Lin5064’, consistently expressed relatively low levels of disease despite high frequencies of virulence in the pathogen and had consistently high D‐values. They may therefore have good levels of partial resistance.     

Multi-trait selection in a diallel crossing scheme of cocoa

Cocoa breeding seeks to increase the yield by area unit. In this context, one must consider the resistance to Phytophthora disease, the most serious one in cocoa culture. Thus, herein two traits were used: yield, i.e. number of healthy pods obtained in 7 years and Phytophthora resistance, estimated by pod rot rate. A combined individual‐family selection is proposed on the basis of the total genetic value in order to spread clonal material. This selection method was applied in a 6 × 6 diallel scheme in Cameroon. The heritability of Phytophthora resistance (near 0.2) was higher than for yield (0.13). A selection index was constructed to obtain good genetic gains on each of the two traits (yield and Phytophthora resistance). To improve prediction of genetic values, a third trait, potential yield, was used. With the chosen weight, the expected genetic gain was about 35% for resistance at 1% level of selection. This selection was applied and a confirmation trial is being established with the selected trees.