The Leaf Color and Trichome Density Influence the Whitefly Infestation in Different Cassava Cultivars

Abstract

The whitefly species Bemisia tuberculata and Aleurotrixus aepim (Hemiptera: Aleyrodidae) are considered important cassava (Manihot esculenta) pests. Leaf color and other morphological characteristics can influence the pest’s interactions with the host plants. Thus, this study aimed to identify the relationship between whitefly occurrence and trichome density and leaf color in different cassava cultivars. The study was conducted in the field during the 2014/2015 and 2016/2017 crop seasons. The whitefly occurrence was surveyed in the cultivars, IAPAR 19, IPR Upira, IPR União, IAC 576-70, IAC 14, IAC 90, Catarina Branca, Santa Helena and Baianinha. The whitefly nymph quantification was correlated with non-glandular trichome density, luminosity (L*) and chroma (a* and b*) of the cassava leaves. IAPAR 19 and IAC 14 were less infested by whitefly nymphs when contrasted with IPR União, IPR Upira and Baianinha, which were the most infested. The lowest B. tuberculata infestations were correlated with lesser trichome density, highest light reflection and highest chroma in the sprout and the plant’s superior third portion leaves. Low A. aepim infestation in both crop seasons made it impossible to verify its correlation with the studied cassava plant characteristics. The cultivars IAPAR 19 and IAC 14 could contribute towards B. tuberculata management in regions with a history of whitefly infestation.

Decoding Antixenotic Mechanism of Resistance in Cassava Genotypes against Whitefly, <i>Bemisia tabaci</i> (Gennadius)

“…The correlation between trichome density and B. tabaci counts showed a positive correlation (0.39) without statistical significance. Previous studies, by Pastório et al (2022), reported the non-glandular nature of cassava trichomes and showed higher B. tuberculata nymph abundance in cultivars with denser trichomes on sprout and apical leaves. Studies on cotton, tomato, potato, pepper and brinjal also revealed increased B. tabaci oviposition to highly pubescent leaves (Oriani et al, 2010;Firdaus et al, 2011;do Prado et al, 2016;Hasanuzzaman et al, 2016).…”

“…The study involved measuring trichome type, length, and spacing, aiming to understand their characteristics. Further, a correlation matrix between trichomes and whitefly population was established using R software (Pastório et al, 2022). For scanning electron microscope (SEM) analysis 1 mm 2 area from the central leaf lobe's median section of each cassava cultivar was carefully excised using a scalpel.…”

Gradual Emergence of East African cassava mosaic Cameroon virus in Cassava Farms in Côte d’Ivoire

“…Cassava varieties cultivated in some zones were more attractive to whiteflies than others. According to Pastório et al [47], cultivars with dark green leaves are the most attractive to whiteflies.…”

Plant resistance against whitefly and its engineering

“…Results have shown that the role of trichomes varies depending on the plant species, highlighting intrinsic variation between plant species. For example, in tobacco and cassava, negative correlation was observed between whitefly resistance and overall trichome density ( Li et al., 2014 ; Pastório et al., 2023 ), whereas in black gram a positive correlation was found ( Taggar and Gill, 2012 ). On the other hand, no significant correlation was identified between whitefly resistance and trichome density in cucumber ( Novaes et al., 2020 ).…”