Using DNA marker to identify groundnut hybrid in groundnut rust resistance research

Abstract

There are many important steps in breeding for rust resistant groundnut cultivar e.g. evaluation of resistance levels, and population building. Groundnut is self-pollinated crop, it has a high rate of self- pollination in the breeding program. The use of DNA to classify hybridization would help to make more accurate selection and speed up the progress of work. The population of this study was from crosses of susceptible cultivars (KKU1 and Tainan 9) and resistant cultivar (NC Ac 17090). It was found that in F1, hybrids had many characteristics in between the parentsícharacters. For example, hybrid of Tainan 9 × NC Ac 17090 had no difference from Tainan 9 in seed weight per plant, width and length of pod, but pod per plant and pod weight per plant had higher values than those of Tainan 9 (high yield cultivar). However, hybrid of KKU2 ×NC Ac 17090 had seed weight per plant, width and length of pod values in between those of parents e.g. lower than KKU 1 but higher than NC Ac 17090. From RAPD technique, 120 primers have been screened. Only one primer (OPO11) showed a difference between NC Ac 17090 and susceptible cultivars (KKU1 and Tainan 9) at 1000 base. So, it was introduced as a tool to select F1 hybrid. The results indicated that F1 hybrids were 56.25 and 57.69% from crosses of Tainan 9 × NC Ac 17090 and KKU 1 × NC Ac 17090 respectively. Results from morphological study confirmed that those plants were from hybridization. Correlation of pustule diameter and number of pustules were significant. Results from F2 indicated that the ratio of susceptible to resistant plants was 15: 1 (p>0.05). However, only 50% of plant with small pustule showed O111000 maker.

Keywords

• RAPD
• groundnut
• hybrid
• rust
• resistance