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

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 {dollar}pm{dollar} 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 F{dollar}sb2{dollar} populations (all RAPD markers were in one F{dollar}sb2{dollar} 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 isozyme EST-3 was monogenically inherited and dominantly expressed. Most RAPD markers segregated in a 3:1 ratio. Marker UBC368{dollar}sb{lcub}425/655{rcub}{dollar} segregated in a co-dominant fashion. The RAPD markers UBC304{dollar}sb{lcub}831{rcub},{dollar} UBC304{dollar}sb{lcub}964{rcub},{dollar} UBC308{dollar}sb{lcub}990{rcub},{dollar} UBC322{dollar}sb{lcub}1432{rcub},{dollar} UBC328{dollar}sb{lcub}831{rcub},{dollar} UBC332{dollar}sb{lcub}1118{rcub},{dollar} UBC3321{dollar}sb{lcub}1581{rcub},{dollar} UBC333{dollar}sb{lcub}617{rcub},{dollar} UBC349{dollar}sb{lcub}752{rcub},{dollar} UBC365{dollar}sb{lcub}1013{rcub}{dollar} and UBC388{dollar}sb{lcub}459{rcub}{dollar} showed distorted segregation.; In two F{dollar}sb2{dollar} populations, PI 283564c.3 x PI 426885.2 and PI 358601.5 x PI 173714.5, a linkage between AAT-2 and SKDH was reconfirmed. In the cross PI 426891.1.3 x PI 283564c.3.2, one morphological, three isozyme and 71 RAPD markers were mapped resulting in the delineation of 14 linkage groups including 69 markers (1 morphological, 3 isozyme and 65 RAPD markers). The total genome length covered by these 75 markers (69 linked and six unlinked) was about 864 cM.; Considering cost, simplicity and abundance, RAPD analysis was more efficient than isozyme analysis in developing linkage map.