Giordano Rosanna, Weber Everett P, Mitacek Ryan, Flores Alejandra, Ledesma Alonso, De Arun K, Herman Theresa K, Soto-Adames Felipe N, Nguyen Minh Q, Hill Curtis B, Hartman Glen L
Institute of Environment, Florida International University, Miami, FL, United States.
Puerto Rico Science Technology and Research Trust, San Juan, Puerto Rico.
Front Microbiol. 2023 Aug 31;14:1209595. doi: 10.3389/fmicb.2023.1209595. eCollection 2023.
Plant breeding is used to develop crops with host resistance to aphids, however, virulent biotypes often develop that overcome host resistance genes. We tested whether the symbionts, () and (), affect virulence and fecundity in soybean aphid biotypes Bt1 and Bt3 cultured on whole plants and detached leaves of three resistant, , and and one susceptible, , soybean genotypes. Whole plants and individual aphid experiments of with and without and did not show differences in overall fecundity. Differences were observed in peak fecundity, first day of deposition, and day of maximum nymph deposition of individual aphids on detached leaves. Bt3 had higher fecundity than Bt1 on detached leaves of all plant genotypes regardless of bacterial profile. Symbionts did not affect peak fecundity of Bt1 but increased it in Bt3 (++) and all Bt3 strains began to deposit nymphs earlier than the Bt1 (+-). in Bt1 delayed the first day of nymph deposition in comparison to aposymbiotic Bt1 except when reared on . For the Bt1 and Bt3 strains, symbionts did not result in a significant difference in the day they deposited the maximum number of nymphs nor was there a difference in survival or variability in number of nymphs deposited. Variability of number of aphids deposited was higher in aphids feeding on resistant plant genotypes. The impact of on soybean aphid patterns of fecundity was dependent on the aphid biotype and plant genotype. alone had no detectable impact but may have contributed to the increased fecundity of Bt3 (++). An individual based model, using data from the detached leaves experiment and with intraspecific competition removed, found patterns similar to those observed in the greenhouse and growth chamber experiments including a significant interaction between soybean genotype and aphid strain. Combining individual data with the individual based model of population growth isolated the impact of fecundity and host resistance from intraspecific competition and host health. Changes to patterns of fecundity, influenced by the composition and concentration of symbionts may contribute to competitive interactions among aphid genotypes and influence selection on virulent aphid populations.
植物育种用于培育对蚜虫具有宿主抗性的作物，然而，往往会出现克服宿主抗性基因的毒性生物型。我们测试了共生菌（）和（）是否会影响在三种抗性大豆基因型（，和）以及一种易感大豆基因型（）的整株植物和离体叶片上培养的大豆蚜虫生物型Bt1和Bt3的毒性和繁殖力。有和没有共生菌的整株植物和单个蚜虫实验在总体繁殖力上没有显示出差异。在离体叶片上观察到单个蚜虫的繁殖力峰值、产卵第一天以及若虫最大产卵日存在差异。无论细菌分布情况如何，在所有植物基因型的离体叶片上，Bt3的繁殖力都高于Bt1。共生菌不影响Bt1的繁殖力峰值，但会提高Bt3（++）的繁殖力峰值，并且所有Bt3菌株开始产卵的时间都比Bt1（+-）早。与无共生菌的Bt1相比，Bt1中的共生菌会延迟若虫产卵的第一天，除非在 上饲养。对于Bt1和Bt3菌株，共生菌在若虫最大产卵日方面没有导致显著差异，在若虫数量的存活或变异性方面也没有差异。取食抗性植物基因型的蚜虫所产蚜虫数量的变异性更高。共生菌对大豆蚜虫繁殖力模式的影响取决于蚜虫生物型和植物基因型。单独存在时没有可检测到的影响，但可能促成了Bt3（++）繁殖力的提高。一个基于个体的模型，使用来自离体叶片实验的数据并消除种内竞争，发现了与温室和生长室实验中观察到的模式相似的结果，包括大豆基因型和蚜虫菌株之间的显著相互作用。将个体数据与基于个体的种群增长模型相结合，分离出了繁殖力和宿主抗性对种内竞争和宿主健康的影响。受共生菌组成和浓度影响的繁殖力模式变化可能有助于蚜虫基因型之间的竞争相互作用，并影响对毒性蚜虫种群的选择。
