Inheritance and linkage of morphological, isozyme and RAPD markers in grasspea

Abstract

Experiments were conducted to determine the outcrossing rate, the inheritance of markers and establish a basic linkage map in grasspea, Lathyrus sativus L. The outcrossing rate in a white-flowered line of grasspea ranged from 1.7 to 2.7% among eight combinations of gene frequency and location. The outcrossing rate in this study (2.2 ± 0.7%) suggests that individual lines of grasspea should be maintained in isolation to maintain their genetic integrity. Inheritance and linkage were determined for one morphological, 11 isozyme and 72 RAPD markers in five F2 populations (all RAPD markers were in one F2 population). The inheritance of flower colour was monogenic with colour dominant over white. The isozymes, ACO-1, ACO-2, AAT-1, AAT-2, EST-6, FDH, LAP-1, PGD-2, SKDH and TPI-1, were codominantly expressed with monogenic inheritance. The isozymes LAP-1 and PGD-2 segregated in a non-Mendelian ratios in the crosses PI 426891.1.3 x PI 283564c.3.2 and PI 426891.1 x PI 172930.4, respectively. The isozymeEST-3 was monogenically inherited and dominantly expressed. Most RAPD markers segregated in a 3:1 ratio. Marker UBC368425/655 segregated in a co-dominant fashion. The RAPD markers UBC304831, UBC304964, UBC308990, UBC3221432, UBC328831, UBC3321118, UBC33211581, UBC333617, UBC349752