INHERITANCE AND LINKAGE RELATIONSHIPS OF MORPHOLOGICAL AND ISOZYME LOCI IN CHICKPEA (CICER-ARIETINUM L)

Inheritance and linkage relationships of several morphological and iso zyme loci are described in chickpea (Cicer arietinum L.). Segregation data obtained from several F2 families confirmed the previously observ ed mode of inheritance for most of the morphological loci. Additional morphological markers in chickpea are also described. Most of the isoz yme loci studied showed codominant expression and fit expected Mendeli an segregation ratios. However, distorted ratios were also observed fo r some loci. Linkage was found between Pgd-c, the locus encoding the c ytosolic form of 6-phosphogluconate dehydrogenase, and Hg, the locus c ontrolling plant growth habit. These 2 loci were separated by approxim ately 18 recombinational map units. A similar linkage between comparab le loci was previously reported in pea (Pisum sativum L.) (Weeden and Wolko 1990). Linkage was also detected among 3 isozyme loci; the cytos olic form of phosphoglucomutase (Pgm-c), glucose-1-phosphate transfera se (Gpt1), and the plastid specific form of 6-phosphogluconate dehydro genase (Pgd-p). The linkage of 2 loci (Pgm-c and Pgd-p) in this cluste r is also conserved in pea and lentil (Lens Miller). The linkage betwe en an acid phosphatase locus (Acp3) and the locus specifying the cytos olic form of glucosephosphate isomerase (Gpi-c) in chickpea suggested another linkage group in common with pea. Additionally, other linkages that were not previously observed in chickpea or related genera inclu ded the linkage of the cytosolic form of aconitase (Aco-c) with adenyl ate kinase (Adk1) and fructokinase (Fk3), and the linkage of a locus e ncoding the mitochondrial specific aconitase (Aco-m) with a seed prote in locus (Spr1). The loci determining flower color (P), epicotyl color (Gst), seed coat color (T3), and seed surface (Rs) were associated wi th the locus encoding glucose-1-phosphate transferase (Gpt2). These re sults, along with previous studies, suggest that pea, lentil and chick pea have several common linkage groups consisting of homologous genes. This also indicates that linkages found in one genus can be used to p redict similar linkages in related genera in the development of linkag e maps.