| Title |
Phenotyping dauer juvenile oxidative stress tolerance, longevity and persistence within wild type and inbred lines of the entomopathogenic nematode Heterorhabditis bacteriophora |
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Authors |
Nanette Hope Sumaya, Sitaram Aryal, Bart Vandenbossche, Mike Barg, Verena Doerfler, Olaf Strauch, Carlos Molina, Ralf-Udo Ehlers |
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Publication date |
2017/10/4 |
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Journal |
Nematology |
| Volume |
19 |
| Issue |
8 |
| Pages |
971-986 |
| Publisher |
Brill |
| Abstract |
The commercial use of the entomopathogenic nematode Heterorhabditis bacteriophora as a biocontrol agent against noxious insects is limited due to its relatively short shelf-life. Longevity of dauer juveniles (DJ) during storage and in transit to end users is considerably restricted by environmental stresses. As a derivative stress triggered by environmental factors, oxidative stress causes a strong internal metabolic imbalance leading to lifespan reduction. In this study, the relation between DJ oxidative stress tolerance and longevity in H. bacteriophora was investigated at 25 and 7脗掳C. A strong and significant correlation between DJ oxidative stress tolerance and longevity during storage in Ringer芒聙聶s solution (R=0.802 at 7脗掳C; R=0.604 at 25脗掳C) was recorded. Phenotyping of these traits was performed for 40 H. bacteriophora wild type strain and inbred line collections. At 25脗掳C, the mean time survived in Ringer芒聙聶s by 50% of the DJ (MTS50) ranged from 21 to 57 days, whereas under oxidative stress, survival was from 3 to 22 days. At 7脗掳C, a maximum MTS50 of 94 days was assessed when DJ were stored in Ringer芒聙聶s, while the maximum MTS50 was only 25 days with oxidative stress induction. The heritability of DJ tolerance to oxidative stress, determined by using homozygous inbred lines, is high (h2>0.9), an indication of a high probability for successful selective breeding. In a subset of preselected H. bacteriophora inbred lines, DJ oxidative stress tolerance correlated with the DJ survival (persistence) after application to sand (R=0.719). The study provides fundamental data required for a genetic breeding programme to produce hybrids with improved stress tolerance and prolonged shelf-life and soil persistence. |
| Index terms / Keywords |
dauer survival; environmental stress; heritability; nematode shelf-life; reactive oxygen species; storage temperature |
| DOI |
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| URL |
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Mindanao State
University - Iligan Institute of Technology