抗松材线虫病马尾松种源化学成分与抗性机理研究(第Ⅱ报)——马尾松种源抗性与中性萜类化合物组成差异关系研究

通过气相色谱分析研究了高抗、中抗和敏感马尾松种源中性萜类 (主要是倍半萜类 )化学组成及其差异状况。结果表明 ,不同马尾松种源的抗性是由其内部化学组成决定的 ,是种源的特征性质。高抗种源比中抗和敏感马尾松种源含有更多的长叶烯和α 松油醇 ,而含有较少的反式石竹烯和 β 芹子烯。而且长叶烯与反式石竹烯的含量差越大 。

不同造林模式抗性马尾松种源林成活率及生长测定

从广东、广西地区引进优良的抗性马尾松种子,容器育苗后进行造林示范试验。不同造林模式对抗性马尾松成活率及生长测定结果表明,营造抗性马尾松种源纯林和混交造林,抗性马尾松种源幼林成活率均为93%以上,各造林模式间差异不明显;与杉木混交的抗性马尾松种源林生长缓慢,与其他3种造林模式的抗性马尾松种源幼林高、地径生长存在明显差异。

Screening of Drought Stress Indicators and Analysis of Drought Resistance in Cultivated Rice Germplasm Resources in Guangxi

This study aimed to screen drought stress indicators and analyze the drought resistance in 105 cultivated rice germplasm resources in Guangxi Zhuang Autonomous Region under drought stress in the whole growth period based on D value of seven morphological traits including panicle neck thickness,effective panicle number per plant,1 000-grain weight,filled grain number per panicle,total grain number,seed setting rate and yield per plant.According to the results,under drought stress,yield per plant exhibited significant positive correlation with panicle neck thickness and exhibited extremely significant positive correlation with other five morphological traits.Based on the identification and evaluation of comprehensive drought-resistance index D value,seven highly drought-resistant cultivated rice varieties were screened,accounting for 6.67％.Upland rice germplasm resources in Guangxi Zhuang Autonomous Region possess strong drought-resistance capacity,which could be used to screen highly drought-resistant rice germplasm materials.This study provided material basis and theoretical reference for breeding drought resistant rice cultivars in Guangxi Zhuang Autonomous Region.

Resistance Evaluation of Eggplant Resources to Verticillium wilt in Sichuan Province

[Objective] Aimed to lay a scientific foundation for eggplant resistant breeding, the resistant field identification of eggplant resources to Verticillium wilt was carried out. [Method] Test materials were 35 eggplant resources, which were collected from various places in Sichuan province since 2001. These eggplant resources were made resistance evaluation to Verticillium wilt by watering injured roots with Verticillium dahliae spore suspension. [Result] The eggplant resources had good resistance to Verticillium wilt. Among 35 evaluated resources, 10 resources like 242-9OP, 41-1,35-R5, etc. were resistant, while 23 resources like 68 ×47, Zizaoqie, 32-1, etc. were tolerant. Some resistant resources like 41-1,35-R5, 47-R1, etc. had been transferred into new resistant varieties like EF9910, etc. by breeding institutes. [Conclusion] The resistant level and future resistance breeding direction of eggplant resources in Sichuan were clarified by the resistance evaluation of eggplant resources so as to provide a technical guidance for eggplant resistance breeding.

Resistance Evaluation of Capsicum spp. Germplasm to Meloidogyne incognita

[Objective] This study aimed to screen out hot pepper germplasms highly resistant to Meloidogyne incognita, thereby providing resistant resources for hot pep- per breeding. [Method] Comprehensive analysis combining cluster analysis and sub- ordinate function was conducted through determining related resistance indexes of 67 hot pepper germplasms 50 days after inoculated with M. incognita. [Result] The effects of M. incognita on related resistance indexes were significantly different am- ong the hot pepper germplasms. Egg index and gall index had abundant genetic variation with variation coefficients of 143.16% and 118.95%, respectively. Based on the gall indexes, cluster analysis of hot pepper germplasms was performed. The 67 hot pepper germplasms were divided into 4 groups （resistant, moderately resistant, susceptible and high susceptible）. The resistance intensity of the hot pepper germplasms were ranked according to the sum of subordinate function values of various resistance indexes. The total function values of Rela 2 and L506M were the largest （2.00）, indicating that these two germplasms were immune to M. incognita. The total function values of L287-2, L522-1M, L504M, L515-2, 13SM100-1, L512M, L292-1, L319, L316, L317, 13SM87-1 and Rela 5 were larger than 1.95, indicating that these germplasms were highly resistant to M. incognita. [Conclusion] This study could provide certain resistant resources for resistance breeding of hot pepper to M. incognita.

Evaluation of Drought Resistance of Olive Varieties from Different Provenances

In order to study olive’s drought resistance in Yunnan province, different varieties of olive trees from Albania, Italy, Spain and Greece were cultured, and leaves from these trees in drought season and rainy season were col ected and determined by physiological indices, such as proline content, relative electric con-ductivity, binding water/free water, relative water content and malon-dialdehyde in leaves. The evaluation of drought resistance with subordinate function showed that：There were no significant differences among drought resistances of varieties and provenances. The change of physiological indices in different varieties showed differ-ent ranges. The drought resistance of seven varieties decreased in order as fol ows：Koroneiki〉 Picual〉 Berat〉 Kaliniot〉 Frantoio〉 Coratina〉 Arbequina.

Screening Winter Wheat Germplasm for Fusarium Head Blight Resistance

58 winter wheat breeding lines and 4 widely popularized varieties in Huaihe River wheat production regions of Anhui were used to screen resistant germplasms to Fusarium head blight. Incidence, disease index, percentage of infected kernels and DON content in the kernels were measured for each variety or line following artificial inoculation of Fusarium spp. pathogens. Reactions of wheat to Fusarium infection varied among genotypes and different types of resistance. The incidence of infection for each variety or line highly correlated to the severity of colonization after infection. DON content was more correlated to the percentage of kernels infected than to the overall incidence or severity. The selected control varieties were all susceptible to FHB, while seven breeding lines demonstrated good resistant performance. New FHB resistant winter wheat varieties appealing to the actual needs are expected from them.

Provenance-specific ecophysiological responses to drought in Cunninghamia lanceolata

Aims Cunninghamia lanceolata is one of the most important coniferous species in southern China,but its high sensitivity to drought restricts its expansion.Understanding the intraspecific variation of physiological responses to drought can help us manage this plantation better.Methods We selected 3-year-old seedlings of C.lanceolata,which originated from the low precipitation(LP),middle precipitation(MP)and high precipitation(HP)habitats,respectively.Seedlings were grown under drought stress(20%of soil volumetric water content)for 40 days.The ecophysiological responses and adaptive strategies with different drought tolerance were investigated.Important Findings LP provenance possessed the best tolerance to drought stress,suggesting that considerably increased carbohydrates and nitrogen-containing compounds as osmotic protective materials,which were driven by fast carbon and nitrogen metabolisms.In addition,the highest peroxidase activity could effectively eliminate hydrogen peroxide in drought-stressed LP provenance.The MP provenance reserved a large amount of non-structural carbohydrates,which may act as a certain buffer for encountering drought stress.Importantly,timely closure of stomata to reduce needle transpiration when encountering a water deficiency would help them adapt to long-term drought.MP provenance adopted a conservative water-saving strategy.However,HP provenance regulated root growth(increased root/shoot ratio)and reduced penetration potential to help them absorb water.The different strategies among provenances may be related to the long-term domestication of the geographical environments.Therefore,our results underline the importance of provenance-specific responses to drought stress.It is highly significant to accelerate the selection of drought-resistant germplasms and to cultivate high-yield plantations in the future.