Inheritance of natural seed-coat cracking in chickpea

A spontaneous mutant with natural seed-coat cracking, designated "cracked seed-coat mutant (CSM)," was identified in chickpea (Cicer arietinum L.) from an F(2) population of a cross ICRISAT chickpea (ICC) 10301 × ICC 12430. The extent of seed-coat cracking (SCC) varied widely from a minute to several wide cracks. Seed coats showed cracks before seeds were fully developed and the plants had reached physiological maturity. However, seed-coat cracks were most visible on dry matured seeds, particularly in desi types. Two loci (Scc-1 and Scc-2) that controlled SCC were identified. F(1) plants from the crosses of CSM with desi genotypes produced seeds with no SCC, whereas F(1) plants from the crosses of CSM with kabuli genotypes produced seeds with SCC. F(2) segregation followed 13:3 and 7:9 ratios for plants without SCC and with SCC in CSM × Desi and CSM × Kabuli crosses, respectively. Three alleles were identified at the first locus (Scc-1) from CSM (Scc-1 (c)), desi (Scc-1 (d)), and kabuli (Scc-1 (k)) types, with the dominance relationship being Scc-1 (d) > Scc-1 (c) > Scc-1 ( k ). At the second locus (Scc-2), CSM had the dominant allele (Scc-2), whereas both desi and kabuli types had the recessive allele (scc-2). The SCC trait showed no linkage with leaf type (pinnate vs. simple) and flower color (pink vs. white) and had no adverse effects on grain yield. The SCC trait may facilitate dehulling and preparation of splits (dal), but the cracked seed would be prone to damage by insect pests and unfavorable moisture conditions.