Relationship between SSR- Based Molecular Marker and Cotton F<SUB>1</SUB> Inter Specific Hybrids Performance for Seed Cotton Yield and Fiber Properties

Abstract

Knowledge of genetic diversity and relationships among breeding materials has a significant impact on crop improvement. Association between parental divergence and progeny performance has not been well documented in cotton ( Gossypium hirsutum L.). The objectives of this study were to estimate genetic diversity among selected cotton genotypes on the basis of simple sequence repeat (SSR) markers, and to investigate the relationship between genetic diversity and F 1 population performance and heterosis.The present study was conducted to investigate the relationship between parents molecular marker diversity and inter specific hybrids of cotton to evaluate the hybrid performance and heterosis using molecular markers. Twenty eight F 4 lines of ( Gossypium barbadense L.) were crossed with the four common diverse testers ( Gossypium hirsutum L.) viz., DH 98-27 (T 1 ), ZCH8 (T 2 ), 178-24 (T 3 ) and DH 18-31 (T 4 ) to produce 112 F 1 inter specific hybrids during 2010. These 112 F 1 hybrids, their F 5 barbadense lines with 4 hirsutum testers and ruling commercial check (MRC6918 and DCH32) were evaluated for yield and fiber quality traits and sown during kharif 2011 at University of Agricultural Sciences, Dharwad, India. Genetic distances (GD) among the parents were calculated from 40 microsatellite marker data, and their correlation with hybrid performance and heterosis were analysed. The dendrogram constructed from the pooled data revealed three distinct clusters. One cluster involved testers and other clusters showed all lines were placed which are already having proven record in giving good hybrids. The similarity coefficient values between the line DB 533 x DB 534 F 4 IPS 49 and the tester DH 98-27 showed 67%. It revealed that DB 533 x DB 534 F 4 IPS 49 was closely related to DH 98-27 with 67% similarity between parents. The hybrid between DB 533 x DB 534 F4 IPS 49 and DH 98-27 exhibited the highest yield of 2884.26 kg/ha. Similarity coefficient (88%) value between lines and testers showed between the line DB 533 x DB 534 F 4 IPS 52 and the tester ZCH8, the hybrid between these recorded an yield of 2040.757 kg/ha. Lowest similarity coefficient value was noticed between the line DB 533 x DB 534 F 4 IPS 16 and tester DH 98-27 which revealed that they are far distinct from each other. This combination exhibited 2384.62 kg/ha yield. Genetic distance (GD) ranged from 0.041 to 0.429, with an average of 0.183. The result implied that each cluster dendrogram substantially reflected its own genetic relationship among parents. Overall, a low significant correlation of GD with hybrid performance and heterosis was detected in Table 2~6. Highly significant positive correlation were found between genetic distance (GD) and ginning outturn for F 1 performance (0.277) and heterosis over MRC 6918 (0.279) and DCH 32 (0.279), while significant positive correlation were found between genetic distance (GD) and ginning outturn for mid parent heterosis (0.237). Highly significant positive correlation were found between genetic distance (GD) and seed cotton yield for F 1 performance (0.359) and heterosis over Bt check MRC 6918 (0.336) and over non Bt check DCH 32 (0.362), while significant positive correlation were found between genetic distance (GD) and seed cotton yield for mid parent heterosis (0.226). Significant positive correlation were found between genetic distance (GD) and lint index for mid parent heterosis (0.227), F 1 performance (0.251) and heterosis over MRC 6918 (0.250) and DCH 32 (0.250), while significant positive correlation were found only between genetic distance (GD) and fiber micronaire value for F 1 performance (0.241).