scholarly journals Genetic diversity inMelanaphis sacchariand host-plant resistance in sugarcane

2016 ◽  
Author(s):  
Samuel Nibouche
Author(s):  
K. Satish ◽  
S. Muniswamy ◽  
G. Girish ◽  
Vikas Kulkarni ◽  
J.R. Diwan ◽  
...  

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. 


2010 ◽  
Vol 100 (6) ◽  
pp. 727-734 ◽  
Author(s):  
A.P. Michel ◽  
W. Zhang ◽  
M.A. Rouf Mian

AbstractThe soybean aphid, Aphis glycines Matsumura, is a recent invasive pest of soybean in North America. Currently, much research is focused on developing and characterizing soybean cultivars expressing host-plant resistance. During the initial phases of host-plant resistance screening, many of these studies use soybean aphid laboratory populations. Previous studies in other systems have documented substantial differences among laboratory and field populations. Whether or not this pattern exists in A. glycines is unknown, but it is extremely important when estimating the level of selection and virulence to host-plant resistant soybeans. In this study, we used seven microsatellite markers to estimate and compare genetic diversity and differentiation among five laboratory and 12 field populations. Our results indicate that soybean aphid laboratory populations are severely lacking in genotypic diversity and show extreme genetic differentiation among each other and to field populations. Continued use of laboratory populations for initial soybean aphid resistance screening could lead to erroneous estimations of the potential success for host-plant resistance.


Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1384
Author(s):  
Dinar S. C. Wahyuni ◽  
Young Hae Choi ◽  
Kirsten A. Leiss ◽  
Peter G. L. Klinkhamer

Understanding the mechanisms involved in host plant resistance opens the way for improved resistance breeding programs by using the traits involved as markers. Pest management is a major problem in cultivation of ornamentals. Gladiolus (Gladiolus hybridus L.) is an economically important ornamental in the Netherlands. Gladiolus is especially sensitive to attack by western flower thrips (Frankliniella occidentalis (Pergande) (Thysanoptera:Thripidae)). The objective of this study was, therefore, to investigate morphological and chemical markers for resistance breeding to western flower thrips in Gladiolus varieties. We measured thrips damage of 14 Gladiolus varieties in a whole-plant thrips bioassay and related this to morphological traits with a focus on papillae density. Moreover, we studied chemical host plant resistance to using an eco-metabolomic approach comparing the 1H NMR profiles of thrips resistant and susceptible varieties representing a broad range of papillae densities. Thrips damage varied strongly among varieties: the most susceptible variety showed 130 times more damage than the most resistant one. Varieties with low thrips damage had shorter mesophylls and epidermal cells, as well as a higher density of epicuticular papillae. All three traits related to thrips damage were highly correlated with each other. We observed a number of metabolites related to resistance against thrips: two unidentified triterpenoid saponins and the amino acids alanine and threonine. All these compounds were highly correlated amongst each other as well as to the density of papillae. These correlations suggest that papillae are involved in resistance to thrips by producing and/or storing compounds causing thrips resistance. Although it is not possible to distinguish the individual effects of morphological and chemical traits statistically, our results show that papillae density is an easy marker in Gladiolus-breeding programs targeted at increased resistance to thrips.


2021 ◽  
Vol 22 (11) ◽  
pp. 5941
Author(s):  
Abigail Ngugi-Dawit ◽  
Isaac Njaci ◽  
Thomas J.V. Higgins ◽  
Brett Williams ◽  
Sita R. Ghimire ◽  
...  

Pigeonpea [Cajanus cajan (L.) Millspaugh] is an economically important legume playing a crucial role in the semi-arid tropics. Pigeonpea is susceptible to Helicoverpa armigera (Hübner), which causes devastating yield losses. This pest is developing resistance to many commercially available insecticides. Therefore, crop wild relatives of pigeonpea, are being considered as potential sources of genes to expand the genetic base of cultivated pigeonpea to improve traits such as host plant resistance to pests and pathogens. Quantitative proteomic analysis was conducted using the tandem mass tag platform to identify differentially abundant proteins between IBS 3471 and ICPL 87 tolerant accession and susceptible variety to H. armigera, respectively. Leaf proteome were analysed at the vegetative and flowering/podding growth stages. H. armigera tolerance in IBS 3471 appeared to be related to enhanced defence responses, such as changes in secondary metabolite precursors, antioxidants, and the phenylpropanoid pathway. The development of larvae fed on an artificial diet with IBS 3471 lyophilised leaves showed similar inhibition with those fed on an artificial diet with quercetin concentrations with 32 mg/25 g of artificial diet. DAB staining (3,3’-diaminobenzidine) revealed a rapid accumulation of reactive oxygen species in IBS 3471. We conclude that IBS 3471 is an ideal candidate for improving the genetic base of cultivated pigeonpea, including traits for host plant resistance.


Planta ◽  
2021 ◽  
Vol 253 (2) ◽  
Author(s):  
Subramaniam Gopalakrishnan ◽  
Vadlamudi Srinivas ◽  
Nimmala Naresh ◽  
Sambangi Pratyusha ◽  
Sravani Ankati ◽  
...  

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