Elucidating effect of different photosynthetic pigments on Lipaphis erysimi preference and population build‐up on diverse Brassica juncea genotypes

Abstract

Brassica juncea is the most important oilseed crop in India, and Lipaphis erysimi is a major pest of this crop. The study aimed at knowing the role of photosynthetic pigments in host preference and population build‐up by L. erysimi on diverse B. juncea genotypes. We found significant differences among test genotypes for aphid preference, multiplication rate and population build‐up, and chlorophyll A, chlorophyll B, total chlorophyll, total carotenoids and Soil Plant Analysis Development (SPAD) chlorophyll and Normalised Difference Vegetation Index (NDVI) values in healthy and aphid damaged flowers, immature siliquae and grain filled siliquae. The L. erysimi damage reduced all the photosynthetic pigments across plant parts of test B. juncea genotypes. The aphid damage resulted in change in chlorophyll B in flowers and total chlorophyll in immature siliquae showed positive association with leaf preference, while total carotenoids in flowers and grain filled siliquae had negative association with leaf and bud preference by L. erysimi. Chlorophylls A and B in the siliquae showed significant and positive association with multiplication rate and population build‐up of L. erysimi on B. juncea. Change in chlorophyll A, total chlorophyll and total carotenoids because of aphid damage contributed to 38.6% variation in host preference and 21.9% variation in multiplication rate and population build‐up of L. erysimi on different B. juncea genotypes. Genotypes PM 30, RH 749, PDZ 6, Pusa 119‐1‐3, Pusa 119‐1‐1 and Kranti were found with least leaf and bud preference, lower aphid multiplication rate and population build‐up, and higher amounts of different chlorophylls and total carotenoids, suggesting their use in aphid resistance breeding programme.

Aphid‐induced phytochemicals in Brassica juncea (L.) Czern & Coss. afflicting host preference and bionomics of Lipaphis erysimi (Kaltenbach)

“…Furthermore, a significant and positive association amid chlorophyll A and siliquae preference suggests that chlorophyll A is involved in the establishment of L. erysimi . Similarly, previous studies have shown a significant reduction in chlorophyll content in B. juncea genotypes due to L. erysimi feeding, as well as a positive association with L. erysimi population build‐up (Samal et al., 2022). Furthermore, greenbug feeding reduced chlorophyll levels in the host plant, affecting the photosynthetic process (Ma et al., 1998).…”

“…In addition, selecting and establishing a suitable host plant are essential phases in the interaction between insects and plants (Thorsteinson, 1960). It is primarily regulated by visual cues, which mostly consist of photosynthetic pigments (Dilawari & Atwal, 1989; Hardie, 1980; Samal et al., 2022). Aphids use olfactory cues to locate hosts, while visual cues are more important (Finch & Collier, 2000; Kostal & Finch, 1994; Prokopy & Owens, 1983).…”

“…Diversification in host quality, which can be seen in the amounts of secondary compounds present or in the nutrients that aphids need, may account for variations in performance on different cultivars of host plants. Different host plants have different biochemicals, such as different photosynthetic pigments, secondary metabolites, nutrient balance and enzymes, which further deviate from the constitutive level upon infestation and subsequently affect herbivore insect population intensities in different ways (Bhoi et al., 2020; Samal et al., 2021, 2022; Sau et al., 2022). Similar trends of variation in total proteins, sugars, phenols, tannins, antioxidants and FRAP were also noted in the current study as a result of L. erysimi infestation.…”

Comprehensive analysis of the 2R‐MYB family in Nicotiana tabacum and functional characterization of NtMYB35 in pigment metabolism

“…Additionally, these pigments are also implicated in the plant's response to various stresses. Previous studies have shown the disruption of chloroplast function and changes in the contents of chlorophylls and carotenoids could influence aphid feeding preferences, multiplication rate, and population build‐up (DeBlasio et al, 2018; Ipsita et al, 2022). Given that ntmyb35 mutant plants were more susceptible to aphid infestation in the field, we conducted an evaluation of aphid resistance in wild‐type, overexpression, and mutant plants by inoculating them with an equal number of aphids under controlled conditions.…”

Nucleo-cytoplasmic interactions affecting biological performance of Lipaphis erysimi in Brassica juncea

“…The parthenogenetic viviparity, high fecundity, and host specificity support L. erysimi to multiply faster on Brassica plants. The interaction between olfactory cues like plant volatiles and visual stimuli including photosynthetic pigments are crucial for host plant finding by the aphids ( Hardie, 1980 ; Dilawari and Atwal, 1989 ; Samal et al, 2022 ). Due to non-availability of aphid resistance sources in the primary gene pool of brassicas ( Rana, 2005 ), the only effective and easily available strategy to control this pest is through systemic insecticides ( El-Wakeil et al, 2013 ).…”