Integrating QTL mapping and transcriptome analysis to provide molecular insights into gynophore-pod strength in cultivated peanut (.).

INTRODUCTION

Gynophore-pod strength is one of important mechanical properties that affect mechanized harvesting quality in peanut. Yet its molecular regulation remains elusive.

METHODS

We measured gynophore-pod strength across three environments using a recombinant inbred line (RIL) population derived from a cross between Yuanza9102 and Xuzhou68-4, followed by QTL mapping. Lines with extreme gynophore-pod strength from the RILs were selected to perform anatomical analysis and transcriptome analysis to elucidate the underlying molecular mechanisms governing gynophore-pod strength.

RESULTS AND DISCUSSION

Both genotypic factor and environments affected gynophore-pod strength significantly, and its broad sense heritability ( ) was estimated as 0.77. Two QTLs that were stable in at least two environments were detected. was mapped 4cM (about 1.09Mb) on chromosome A05, and was mapped 3cM (about 1.71Mb) on chromosome B02. Anatomical analysis showed higher lignin content in lines with extreme high gynophore-pod strength compared to those with extreme low gynophore-pod strength. Additionally, comparative transcriptome analysis unveiled that phenylpropanoid biosynthesis was the main pathway associated with high gynophore-pod strength. Further, we predicted and as the candidate genes for and , respectively. The two stable QTLs and their associated markers could help modify gynophore-pod strength. Our findings may offer genetic resources for the molecular-assisted breeding of new peanut varieties with improved mechanized harvesting quality.