Identification of molecular markers for mungbean (Vigna radiata (L.) Wilczek) bruchid (Callosbruchus chinensis Linnaeus) resistance by random amplification of bulked genomic DNA samples.

Date

10-2002

Degree

Bachelor of Science in Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Merlyn S. Mendioro

Abstract

To identify Random Amplified Polymorphic DNA (RAPD) markers that are potentially linked to the Bruchid resistance gene, 200 recombinant inbred lines from a cross between NM 92 (cultivated variety) and TC 1966 (a V.radiata var. sublobata accession resistant to bruchid) were bioassayed and the DNA were extracted. Results from the bioassay revealed that 44 were highly resistant (Seed damage = 0 percent), while 38 were highly susceptible (Seed Damage _.c80 percent). The DNA of resistant individual plants were bulked into two (R1and R2) and so were the DNA from susceptible individuals (S, and S2). Both R1 and R2 were composed of 22 individuals while S1 and S2 were composed of 20 and 18 individuals, respectively. Parental DNA was screened using 240 Operon primers and 379 UBC primers for polymorphism. A total of 158 Operon primers and 204 UBC primers were able to distinguish polymorphism between the parents and these primers were subsequently used in screening the bulk samples and the two nearly isogenic lines (NILs). From a total of 360 primers used in screening of bulked samples, nine were found to produce band fragments unique to resistant bulks. However, the unique band fragments produced by four primers (Operon T 20, Operon U 11 Operon W 13 and UBC 353) were also found in the susceptible NIL. Thus, these primers cannot be used as markers for the gene. On the other hand, band fragment produced by UBC 374 was not observed in the resistant NIL. Thus, this primer cannot be used as marker for the gene as well. However, four primers (Operon T 16, Operon V 02, UBC 193 and UBC 313) produced fragments unique to the resistant samples including the resistant NIL. Thus, there is a possibility that these fragments are linked in cis with the bruchid resistance gene for they cosegragate.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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