MAGIC lines in chickpea: development and exploitation of genetic diversity
In chickpea a multi-parent advanced generation intercross (MAGIC) population was developed using eight parents that are improved varieties and widely adaptable breeding lines. The main objective was to enhance the genetic diversity and bring novel alleles for developing superior chickpea varieties. The development scheme involved a sequence of 28 two-way, 14 four-way and 7 eight-way crosses, followed by bulking of final F1 plants. From F2 generation onwards single plants were grown as progenies and advanced to F8 by single seed descent method. The finally developed 1136 MAGIC lines were phenotyped under rainfed (RF) and irrigated (IR) conditions for 2 years (2013 and 2014) under normal season, and one year under heat stress (HS) condition (summer-2014) in field to estimate the genetic diversity created among these lines. Under RF-2014, RF-2013, IR-2014, IR-2013 and S-2014 seasons 46, 62, 83, 50 and 61 lines showed significantly higher grain yield than the best parent, respectively. Similarly, 23 and 19 common lines were identified under RF and IR conditions over two years and no common line was identified between RF/IR and HS conditions. Preliminary evaluation showed a large variation among MAGIC lines for flowering time (34–69 days), maturity (80–120 days), plant height (23.3–65 cm), grain yield (179–4554 kg/ha), harvest index (0.10–0.77) and 100 seed weight (10–45 g) under RF and IR conditions. Several genotypes with higher grain yield than the best check under heat stress were identified. These MAGIC lines provide a useful germplasm source with diverse allelic combinations to global chickpea community.