Development and characterization of gamma ray and EMS induced mutants for powdery mildew resistance in blackgram

Abstract

Purpose

During post-rainy and rice fallow cropping seasons, popular blackgram varieties are severely affected by powdery mildew leading to severe yield loss. The lack of natural genetic variability for powdery mildew resistance in blackgram germplasm warrants mutation breeding. Hence, in this study, blackgram cultivar CO6 was mutagenized with gamma ray and ethyl methanesulphonate (EMS) to create variability for powdery mildew resistance.

Materials and methods

Seeds of blackgram CO6 were irradiated with three doses of gamma ray (200 Gy, 300 Gy and 400 Gy) followed by two doses of ethyl methanesulphonate (EMS; 20 and 30 mM) to achieve six combination treatments. Selected resistant mutants of M₂ generation were characterized for agronomic, histological, enzyme and biochemical traits along with powdery mildew resistant LBG 17 and susceptible CO6 checks. Molecular variability was studied using 72 simple sequence repeat (SSR) markers.

Results

In the M₂ generation, 60 powdery mildew resistant mutants were identified and a total of 25 high yielding mutants were evaluated further to confirm powdery mildew resistance and yield. Nine resistant mutants (PM 13, PM 20, PM 21, PM 42, PM 53, PM 54, PM 56, PM 57 and PM 60) and the resistant check (LBG17) showed significantly higher values for leaf density, trichome density, SOD, CAT, POX, PPO, total phenols, phytic acid and silica content. SSR markers viz., CEDG154, CEDG290, CEDG139, CEDG259, CEDG191, CEDG024, CEDG 282, CEDG 166, CEDG 232 and CEDG 088 were found polymorphic between resistant mutants and the parent CO6.

Conclusion

The study has demonstrated that sufficient variability was induced in the blackgram for powdery mildew resistance. The elevated levels of SOD, CAT, POX, PPO, total phenols, phytic acid, and silica content observed in selected mutants may be attributed to powdery mildew resistance. The superior mutants identified in this study may be used as donors for the development of powdery mildew resistant lines or released as a new variety.

Keywords:

• Blackgram
• biochemical and molecular characterization
• gamma ray
• EMS
• powdery mildew
• resistant mutants

Acknowledgment

The authors are grateful to the Department of Pulses at Tamil Nadu Agricultural University, Coimbatore for providing research facilities. Dr. Andrew Peter Leon and Dr. A. Karthikeyan provided invaluable guidance and support during the study process.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The Board of Research in Nuclear Sciences (BRNS), Bhabha Atomic Research Center, Trombay, Mumbai-400 085, India, funded this research through the GOI-DAE-BRNS scheme.

Notes on contributors

Murugesan Tamilzharasi

Murugesan Tamilzharasi, PhD, in Genetics and Plant Breeding, is a Research Scholar at Center for Plant Breeding and Genetics, TNAU, Tamil Nadu, India.

Dharmalingam Kumaresan

Dharmalingam Kumaresan, PhD, in Genetics and Plant Breeding, is a Professor at Center for Plant Breeding and Genetics, TNAU, Tamil Nadu, India.

Venkatesan Thiruvengadam

Venkatesan Thiruvengadam, PhD, in Genetics and Plant Breeding, as an Associate Professor in Center for Plant Breeding and Genetics, TNAU, Tamil Nadu, India.

Jegadeesan Souframanien

Jegadeesan Souframanien, PhD, in Life science, Scientist in Nuclear Agriculture & Biotechnology Division, BARC, Mumbai, India.

T. K. S. Latha

T. K. S. Latha, PhD, in Plant Pathology is an Assistant professor in the Department of Plant Pathology, TNAU, Tamil Nadu, India.

N. Manikanda Boopathi

N. Manikandan Boopathi, PhD, in Plant Biotechnology as an Associate professor at Center for Plant Molecular Biology & Biotechnology, TNAU, Tamil Nadu, India.

Palaniappan Jayamani

Palaniappan Jayamani, PhD, in Genetics and Plant Breeding, is a Professor at Center for Plant Breeding and Genetics, TNAU, Tamil Nadu, India.