The Genetic Diversity of Maize Classified by Random Amplified Polymorphic DNA (RAPD)

Prawit Puddhanon¹, T.D. Phillips² and G.B. Collins²

 

1.                          Fulbright visiting scholar 1998, Department of Agronomy, Faculty of Agricultural Production.  Maejo University, Chiang Mai, Thailand.

2.                          Department of Agronomy, Agricultural Science Center North, University of Kentucky, Lexington KY 40546-0091, U.S.A.

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In a maize breeding program, plant breeder always look for sources of germplasm and genetic diversity in order to develop the high yielding varieties.  The maize germplasm were deliberately stored and classified the different backgrounds by morphological traits such as seedling colour, plant type, maturity, seed colour as well as grain yield.  It usually takes two or more seasons to complete the process

Recently, the DNA-based genetic markers had been developed and used extensively in many kinds of crops in order to assist plant breeders to classify their germplasm and genetic diversity more efficiently in term of time and labour cost.  In this study, the Random Amplified Polymorphic DNA (RAPD) was employed to classify 17 maize genetic diversities.  The mini-prep DNA extraction was conducted with the first to fourth leaves of 8-10 grams fresh weight, during 12-14 days after germination.  The stage was appropriate for the genomic DNA extraction resulted in considerable high DNA concentration average of 664 ug/mL.  The genomic DNA was amplified by PCR reaction using 10 Operon Technology primers.  Most of RAPD profiles distributed between 500-2,000 bp and seven DNA polymorphisms were visualized from the amplification of 10 primers by 1.2% agarose gel electrophoresis.  The OPF20 5’(GGTCTAGAGG) 3’primer proved as the suitable primer, it amplified 2 polymorphic DNA with clear bands called OPF20a-1050 and OPF20b-600.  Six different groups of maize genetic background were classified by the RAPD marker using Unweighted Pair Group Method with Arithmetic Average clustering (UPGMA) and NTSYS-pc V. 2.02e software.  The six groups of the maize genetic diversities were ranking from the most similar (1.000) to the lower levels of similar genetic backgrounds (0.272).  The first group (1.000) had seven numbers; G10, G39, G42, G52, G44, G40, and G41.  The second group (0.909) had two members; G24 and G32.  The third group (0.889) had two members; G27 and G35.  The fourth group (0.857) had four members; G3, G26, G20, and G34.  The fifth (0.833) had one member; G19 and the sixth group (0.727) had one member; G28.  It was suggested for the maximum heterosis and hybrid vigour that the member of the first group; G10, G39, G42, G52 could be chosen as S1 female parent and either member of the fifth group; G19 or the sixth group; G28 could be chosen as S1 male parent or tester in the maize breeding program.  The result will be further verified by using the conventional breeding methods in Thailand.

 

 

 

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