Resistance of Major and Backup Rice Cultivars against Ustilaginoidea virens in Anhui Province

[Objective] The aim was to study resistance of major and backup rice cul- tivars against Ustilaginoidea virens. [Method] Experiments and surveys were made on resistance of seventeen backup rice cultivars and some major cultivars in Anhui Province to identify resistance of different rice cultivars. [Result] Yanjing No.9, 80You 226, Tianxie No.l, A01 Xian, Lvjingnuo No.6 were moderate resistant; A03 Xian and Yangjing 636 were susceptible and the rest ten showed moderate susceptibility. Based on surveys on major rice cultivars, most of Liangyou rice series are suscept- able and novel Liangyou Xiang 4 enjoys resistance to certain extent. [Conclusion] The research provided references for resistance of rice against diseases in Anhui Province.

Screening of Rice Stripe Virus(RSV)-resistant Germplasm from Landraces of Rice(Oryza sativa L.)

[Objective] The aim of this study was to screen rice strip virus （RSV）-resistant landraces. [Method] The resistance of 119 rice landraces to rice stripe virus was identified in field spontaneously infected with smal plant-hopper. [Result] There were 55 landraces resistant to rice strip disease in 56 indica rice landraces, but on-ly two resistant to rice strip disease in 63 japonica rice landraces. [Conclusion] The results revealed that there were abundant rice landscapes resistant to RSV in Chi-na, and these varieties can be used to develop more genes resistant to RSV.

Control Effect of 35% Thiamethoxam-prochloraz FS to Plant Diseases and Insect Pests at Rice Seedling Stage and Safety Evaluation

The prevention and control effect of 35% thiamethoxam-prochloraz FS to rice thrips and rice bakanae disease and its influence on the quality of rice seedlings were studied. The results show that when 100 kg of rice seeds were coated with 200 g of 35% thiamethoxam-prochloraz FS,the control effects to rice thrips were 93.0% and 84.7% 15 and 20 days after sowing, and the control effect to rice bakanae disease was 90.8% 30 days after sowing. As 100 kg of rice seeds were coated with 250 g of 35% thiamethoxam-prochloraz FS, the control effects to rice thrips were 98.2% and 94.9% 15 and 20 days after sowing, and the control ef- fect to rice bakanae disease was 94.6% 30 days after sowing. 35% thiamethoxam- prochloraz FS is safe to rice seedlings and can effectively promote the growth of rice seedlings.

Resistance Evaluation of Part of Leading Rice Varieties to Rice Blast in Guangxi Province

In order to determine the resistance of leading rice varieties to rice blast in Guangxi, three natural induction rice blast nurseries were established in Cenxi, Sanjiang and Yongfu. The resistance of the 45 leading rice varieties in Guangxi to rice blast was determined under conditions of spray inoculation and natural induction at seedling stage. The results showed that resistance frequencies of the 45 leading rice varieties ranged from 8.33% to 94.44%. Among the 45 tested varieties, there were 8 varieties of which the resistance frequencies were all higher than 80%, accounting for 17.78%; there were 11 varieties of which the resistance frequencies ranged from 50% to 80%, accounting for 24.44%; the resistance frequencies of the remaining varieties were all lower than 50%, accounting for 57.78% of the total tested varieties. The twoconsecutive-year determination results showed none of the 45 leading rice varieties showed resistance to rice blast. In 2010, there were 26, 12 and 7 varieties that were moderately sensitive, sensitive and greatly sensitive to rice blast respectively, accounting for 57.78%, 26.67% and 15.56% of the total tested varieties. In 2011, there were 16, 23 and 12 varieties that were moderately sensitive, sensitive and greatly sensitive to rice blast respectively, accounting for 35.56%, 51.11% and 13.33%. The overall resistance of the 45 leading rice varieties trended to be decreased year by year. So in rice production, they should be selected properly.

冬季果树管理

一、清洁果园。把果园及其附近的枯枝落叶和杂草清扫干净集中起来高温沤肥或烧毁,以清除病虫害的越冬场所。 二、秋冬耕翻。果园秋冬耕翻,可把地下害虫翻到地面上冻死、干死或被鸟类和其他天敌吃掉。

A Comprehensive Evaluation on Blast-resistant Rice Germplasm Resources in Guizhou Province

Under the condition of natural infection, 60 blast-resistant rice germplasm resources were screened from the blast nursery through many years of natural identifcation, which would provide abundant parent materials for rice blast resistance breeding. The disease level of panicle blast was above grade seven in most of the core materials, including 15 of R grade, 23 of MR grade, 14 of MS grade, 7 of S grade and 1 of HS grade. The results of cross test showed in the F1 generation, 12 rice germplasm resources performed well; and the seed-setting percentages of 17 rice germplasm resources were higher than 50%, and those of 10 were below 5%.

A Resistance Bioassay for Rhizoctonia Root and Crown Rot and Damping-off Caused by the Anastomosis Groups AG 2-2111B and AG 4 in Sugar Beet

In order to determine the level of resistance of sugar beet varieties against Rhizoctonia solani AG 2-21IIB and AG 4, a methodology was implemented under greenhouse conditions that contemplated the most important criteria regarding to plant-pathogen interaction. The effect of plant growth stage on the development of the disease was evaluated. Seven sugar beet varieties were tested for resistance to R. solani AG 2-2IIIB and AG 4. To detect differences in leaf temperature between/L solani inoculated plants and non-infected plants, an infrared （IR） camera was tested. High incidence of R. solani AG 2-2IIIB and AG 4 in sugar beet plants was evident when the fungal inoculum was applied to two and four weeks old plants. At four weeks after sowing, it was the optimum time to inoculate sugar beet plants in order to generate R. solani infection, since at this time all plants were infected. Significant differences were detected regarding disease incidence between sugar beet varieties inoculated with different anastomosis groups. Leaf temperature was significant different between inoculated and non-inoculated plants, demonstrated that this technique could be a new tool for breeders to screen for resistance of new varieties.