Silva L R A, Rodrigues R, Pimenta S, Correa J W S, Araújo M S B, Bento C S, Sudré C P
Laboratório de Melhoramento Genético Vegetal, , , Brasil.
Laboratório de Melhoramento Genético Vegetal, , , Brasil
Genet Mol Res. 2017 Apr 20;16(2):gmr-16-02-gmr.16029631. doi: 10.4238/gmr16029631.
Since 2008, Brazil is the largest consumer of agrochemicals, which increases production costs and risks of agricultural products, environment, and farmers' contamination. Sweet pepper, which is one of the main consumed vegetables in the country, is on top of the list of the most sprayed crops. The bacterial spot, caused by Xanthomonas spp, is one of the most damaging diseases of pepper crops. Genetic resistant consists of a suitable way of disease control, but development of durable resistant cultivars as well as understanding of plant-bacterium interaction is being a challenge for plant breeders and pathologists worldwide. Inheritance of disease resistance is often variable, depending on genetic background of the parents. The knowledge of the genetic base controlling such resistance is the first step in a breeding program aiming to develop new genotypes, bringing together resistance and other superior agronomic traits. This study reports the genetic basis of bacterial spot resistance in Capsicum annuum var. annuum using mean generation analysis from crosses between accessions UENF 2285 (susceptible) and UENF 1381 (resistant). The plants of each generation were grown in a greenhouse and leaflets were inoculated with bacterial strain ENA 4135 at 10 CFU/mL in 1.0 cm of the mesophyll. Evaluations were performed using a scoring scale whose grades ranged from 1.0 (resistant) to 5.0 (susceptible), depending on symptom manifestation. Genetic control of bacterial spot has a quantitative aspect, with higher additive effect. The quantitative analysis showed that five genes were the minimum number controlling bacterial spot resistance. Additive effect was higher (6.06) than dominant (3.31) and explained 86.36% of total variation.
自2008年以来，巴西一直是农用化学品的最大消费国，这增加了农产品生产成本、农产品受污染风险、环境污染风险以及农民受污染风险。甜椒是该国主要消费蔬菜之一，位列喷洒农药最多的作物之首。由黄单胞菌属引起的细菌性斑点病是辣椒作物最具破坏性的病害之一。基因抗性是控制病害的一种合适方法，但培育持久抗病品种以及了解植物与细菌的相互作用对全球植物育种者和病理学家来说仍是一项挑战。抗病性的遗传往往因亲本的遗传背景而异。了解控制这种抗性的遗传基础是育种计划的第一步，该计划旨在培育新的基因型，将抗性与其他优良农艺性状结合起来。本研究利用UENF 2285（感病）和UENF 1381（抗病）两个材料杂交后代的世代平均数分析，报道了辣椒变种辣椒细菌性斑点病抗性的遗传基础。各世代植株在温室中种植，叶片在叶肉1.0厘米处接种浓度为10 CFU/mL的细菌菌株ENA 4135。根据症状表现，使用评分量表进行评估，评分等级从1.0（抗病）到5.0（感病）。细菌性斑点病的遗传控制具有数量性状方面，加性效应较高。定量分析表明，至少有五个基因控制细菌性斑点病抗性。加性效应（6.06）高于显性效应（3.31），解释了总变异的86.36%。
