Abstract
In order to enlarge the potential resources of drought-tolerant peanuts, we conducted in vitro mutagenesis with Pingyangmycin (PYM) as the mutagen as well as directed screening on a medium supplemented with Hydroxyproline (HYP). After being extracted from mature seeds (cv. Huayu 20), the embryonic leaflets were cultured on somatic embryogenesis-induction medium with 4 mg/L PYM and the generated embryos were successively transferred to a germination medium with 4 and then 8 mmol/L HYP to screen HYP-tolerant plantlets. After that, these plantlets were grafted and transplanted to the experimental field. In the next generation, all seeds were sown in the field, and phenotype variation and trait segregation can be observed in most of the offspring (M2 generation). The M3 generation individuals were subjected to drought stress at the seedling stages. The activities of SOD and POD were substantially increased in eight offspring of 11 HYP-tolerant, regenerated plants than in their mutagenic parents. To determine the correlation between mutant phenotypes and genomic modification, we carried out a comparison of the DNA polymorphisms between the mutagenic parents and 13 M3 generation individuals from different HYP-tolerant, regenerated plants with SSR primers. Results showed that most mutants and parent plants had signs of polymorphisms. Under drought stress, some M3 generation individuals of 10 original HYP-tolerant, regenerated plants produced more pods than the mutagenic parent; twenty individuals among them produced >60 g pods/plant. M4-generation seeds were tested for quality characteristics by Near Infrared Spectroscopy (NIS) and nine individuals with higher protein content (>30%) and 21 individuals with higher oil content (>58%) were screened. We concluded that the use of PYM-based in vitro mutagenesis in combination with directed screening with HYP is effective for the creation of potential drought-tolerant mutants of peanut.
Highlights
As one of the key oil crops in China, peanut mainly grows in arid and semiarid areas where biotic and abiotic stresses pose great challenges to its growth and yield [1]
It was determined that 4 mmol/L was the screening concentration for the germination of embryos which were transferred from the induction medium to the germination medium
The results showed that some offspring of 10 of the 13 original HYP-tolerant, regenerated plants produced more pods (> 40 g/plant) than the mutagenic parent, Huayu 20 (33.4 g/plant)
Summary
As one of the key oil crops in China, peanut mainly grows in arid and semiarid areas where biotic and abiotic stresses pose great challenges to its growth and yield [1]. Compared with conventional breeding approaches, mutation-assisted breeding has proven to be more effective in developing cultivars with high resistance to various abiotic stresses [2,3,4,5,6] It usually takes a substantial amount of labor and time to screen the huge quantities of mutants generated via mutation technology. Through the combination of in vitro mutation and tissue culture, the labor and time consumption can be effectively decreased and researchers could rapidly isolate variants with desired agronomic traits. This approach can reduce chimerism, and mutants obtained can be directly used to breed new crop varieties [5, 7,8,9,10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
