Pod Trichome Characterisation Using Foldscope, Morphological Characterization and Genetic Diversity Among Indigenous Collections of Pigeonpea [Cajanus cajan (L.) Millsp.]

Abstract

Background: Association of several morphological traits such as trichome length and trichome density on the pod surface have been found to influence host plant resistance to insect pests. Genetic diversity analysis is used to identify the divergent genotypes and to utilize these genotypes to exploit heterosis. Further, morphological characters are stable across environments owing to oligogeneic nature, they serve as morphological markers in breeding which can be used in varietal or genotypic identification, varietal purification and even in seed production. Hence, the current study aimed to investigate on host plant resistance using portable paper microscope ‘foldscope’, genetic diversity and morphological characters.Methods: A total of 154 germplasm lines with three checks were evaluated in Augmented Block Design (ABD) at Zonal Agricultural Research Station (ZARS), Kalaburagi, during kharif, 2018 to study their genetic diversity. Trichome length and trichome density were recorded using ‘foldscope’ 75 randomly selected genotypes, then correlated with shrivelled seed yield per plot due to pod fly incidence. Morphological characterization of 14 qualitative traits were recorded.Result: Grouping of 157 germplasm lines into twelve clusters indicated a wider genetic diversity for the traits studied, of which 7 clusters were solitary with one entry each. The genotypes with more trichome density and length had less damage by the pod fly. Large variations for morphological characters was observed among the genotypes for qualitative traits such as pod colour, stem colour, flower colour, seed morphology and pod trichomes.

Genetic Divergence for Seed Yield Enhancing and Quality Traits in Pigeonpea [Cajanus cajan (L.) Millsp.]

“…By doing this the possibility of isolating good segregants in segregating generations would be more. These results were in agreement with the earlier work reported by Sharma et al (2018), Ramya et al (2018) and Satish et al (2020).…”

Micro-morphological diversity of rice (Oryza sativa L.) as seen under foldscope

“…Scanning electron microscopic studies of leaf trichomes by Amsagowri (2017) showed that trichome density of rice accessions differ significantly between accessions ranging from 0.41 to 8.56 per mm 2 , and higher trichome density of rice leaves is associated with the lesser ovipositional preference of yellow stem borer thus offering resistance to the pest. Foldscopic study of Satish et al (2020) also showed the presence of significant variation among the pigeonpea genotypes for pod trichome length and density. The trait showed low GCV (9.77) coupled with moderate values of PCV (15.82), heritability (38.12) and GAM (12.38).…”

“…Diwan and Chikkanaragund (2019) studied rice root hair length, length, and density of rice lemma, and trichome . Trichome length and density in pigeon pea (Cajanus cajan (l.) Millsp) observed by Satish et al (2020). In the present study, an effort was made to characterize the 24 elite rice genotypes for their neglected yet useful microscopic morphological traits using Foldscope.…”

Foldscope microscope, an inexpensive alternative tool to conventional microscopy—Applications in research and education: A review

“…However, Yesudhason et al, 2020, and colleagues recently analyzed the same study using a low‐cost foldscope paper microscope. The seven major developmental stages of zebrafish embryos, including zygote, cleavage, blastula, gastrula, segmentation, and pharyngula initiation, as well as their toxicological examination, are observed and documented using a convenient foldscope (Yesudhason et al, 2020), as shown in Figure 2f. As a result, the optical quality of the images observed and captured in a foldscope microscope is comparable to that of a standard research microscope.…”

“…Foldscope can be used to do agrobiodiversity research on crops, animals, insects, microorganisms, crop variability, seeds, and so on (Jayateertha et al, 2018). Using a foldscope microscope, the descriptive information of the foliar micromorphology of Oxalis corniculata was understood, including the presence of hypo stomatous leaves, stomata type, density, distribution, trichomes, crystal deposition, and venation pattern and density, which could be useful in providing taxonomic information (Satish et al, 2020; Shekhawat et al, 2019).…”