Steady expression of high oleic acid in peanut bred by marker-assisted backcrossing for fatty acid desaturase mutant alleles and its effect on seed germination along with other seedling traits.

Sandip K Bera,Jignesh H Kamdar,P Dash,Ajay B Chandrashekar,T Radhakrishnan,N Manivannan,Pasupuleti Janila,Manish K Pandey,Swati V Kasundra,A K Maurya,Mital D Jasani,R P Vasanthi,Rajeev K Varshney,Sahil V Patel,Kirti Rani,K L Dobariya

doi:10.1371/journal.pone.0226252

Abstract

Peanut (Arachis hypogaea L.) is an important nutrient-rich food legume and valued for its good quality cooking oil. The fatty acid content is the major determinant of the quality of the edible oil. The oils containing higher monounsaturated fatty acid are preferred for improved shelf life and potential health benefits. Therefore, a high oleic/linoleic fatty acid ratio is the target trait in an advanced breeding program. The two mutant alleles, ahFAD2A (on linkage group a09) and ahFAD2B (on linkage group b09) control fatty acid composition for higher oleic/linoleic ratio in peanut. In the present study, marker-assisted backcrossing was employed for the introgression of two FAD2 mutant alleles from SunOleic95R into the chromosome of ICGV06100, a high oil content peanut breeding line. In the marker-assisted backcrossing-introgression lines, a 97% increase in oleic acid, and a 92% reduction in linoleic acid content was observed in comparison to the recurrent parent. Besides, the oleic/linoleic ratio was increased to 25 with respect to the recurrent parent, which was only 1.2. The most significant outcome was the stable expression of oil-content, oleic acid, linoleic acid, and palmitic acid in the marker-assisted backcrossing-introgression lines over the locations. No significant difference was observed between high oleic and normal oleic in peanuts for seedling traits except germination percentage. In addition, marker-assisted backcrossing-introgression lines exhibited higher yield and resistance to foliar fungal diseases, i.e., late leaf spot and rust.

Highlights

Peanut or groundnut (Arachis hypogaea L.) is one of the world’s most important legumes for its valuable edible oil and protein content
BC3F2 plants were genotyped with the allele specificpolymerase chain reaction (AS-PCR) and cleaved amplified polymorphic sequence (CAPS) markers, and three plants were identified as homozygous for both the ahFAD2 alleles (Fig 3)
High oil and oleic acid content in the peanuts are necessary for producing superior quality of oil to meet the nutritional needs and for industrial purposes

Summary

Introduction

Peanut or groundnut (Arachis hypogaea L.) is one of the world’s most important legumes for its valuable edible oil and protein content. It is a major cash crop and plays an essential role in the livelihood of millions, especially in semi-arid tropics. It is cultivated globally in around 27.94 million ha with a total production of 47.09 million tons [1]. In China, India, and other Asian countries, half of the produce is crushed for oil extraction and the rest is being used for confectionary and food purposes. Low oil content peanuts are preferred for table purposes and other food preparations of low caloric value

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Results

Conclusion