Morph-agronomic characterization of watermelon accessions with resistance to Fusarium Wilt

Abstract Fifty-five watermelon accessions were inoculated in pots using Fusarium oxysporum f. sp. niveum chlamydospores in a completely randomized design with five replications. Among the 42 accessions that were resistant, twelve accessions with a mean score ≤1 were selected for morpho-agronomic characterization. ‘Sugar Baby’ and ‘Charleston Gray’ were used as controls. Field research was conducted over two production cycles in a randomized block design with three replications and five plants per plot. For the characterization 13 quantitative agronomic traits were used. The dissimilarity measures were obtained by the sum of the matrices of standardized mean Euclidean distance. Coefficients of variation ranged from 5.33% (number of days until 50% of plants with at least one female flower) and 17.20% (mass of characterized fruit). In the second cycle, a reduction in days was observed for the flowering. For soluble solids content, the accession BGH-UNIVASF 40 was statistically equal to the commercial cultivars in the second cycle. Accessions were grouped similarly using two grouping methods, Tocher and the farthest neighbor method. The most promising accessions were BGH-UNIVASF 40, 169, 177 and 210 for use in future hybridizations. BGH-UNIVASF 76, 128 and 185 (Citrullus lanatus var. citroides) can be used as resistant Fusarium wilt rootstocks.

摘要：本研究采用完全随机设计、设置5次重复，以尖孢镰刀菌西瓜专化型（Fusarium oxysporum f. sp. niveum）厚垣孢子对55份西瓜种质资源开展盆栽接种鉴定。在42份表现抗病的种质中，筛选出12份病情指数均值≤1的材料用于形态学与农艺性状表征。以‘Sugar Baby’与‘Charleston Gray’作为对照品种。田间试验在两个生产周期内实施，采用随机区组设计，设置3次重复，每小区定植5株。本次表征共涉及13项量化农艺性状，通过标准化平均欧氏距离矩阵求和法计算种质间的不相似性测度。各性状的变异系数范围为5.33%（50%植株出现至少1朵雌花的天数）至17.20%（鉴定果实的单果质量）。在第二个生产周期中，观测到开花所需天数有所缩短。对于可溶性固形物含量，种质BGH-UNIVASF 40在第二个周期中的表现与商业栽培品种无统计学差异。采用Tocher法与最远邻体法两种聚类方法进行种质分组，两种方法所得聚类结果高度相似。其中BGH-UNIVASF 40、169、177及210这4份种质最具后续杂交育种应用潜力。而BGH-UNIVASF 76、128及185（Citrullus lanatus var. citroides）可作为抗枯萎病砧木材料使用。