DNA Fingerprinting of Brassica Rapa Using SRAP—Sequence-Related Amplified Polymorphism - An Experiment for use in a College Biology Course

Oct 15, 2026

Uploaded by Bulrr

This study applies a direct PCR plus SRAP (Sequence-Related Amplified Polymorphism) approach to Brassica rapa from the Wisconsin Fast Plants system. The experiment aims to help students rapidly identify parental plant types—purple stem and non-purple stem—and distinguish the F1 generation by detecting genetic variations. Results show detectable polymorphism across the Brassica rapa plants that supports separating the three plant types for classroom learning.

LanguageEnglish

CategoryHealthcare

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Pages5

Reading Time13 min

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Abstract

Introduction

Results

Discussion

Methods

Plant Material

DNA Fingerprinting of Brassica Rapa Using SRAP—Sequence-Related Amplified Polymorphism DNA Fingerprinting: An Experiment for use in a College Biology Course Jeff Dykes, Kathleen Johnson, Julia Cousins, Leo Simpson, and Iver Hull Wenatchee Valley College, Omak, WA 98841 Abstract We used a novel approach that combined direct PCR of plant tissue and SRAP DNA fingerprinting to seek to identify the crosses made in Brassica rapa used in the Wisconsin Fast Plants. Our goal was to develop a rapid method for students to use in a biology, botany, or genetics class to identify the parental types (purple stem, non-purple stem) and the F1 generation for Brassica rapa. Our data indicates that there is detectable polymorphism in the Brassica Rapa plants with which to identify the three types of plants. Introduction We continually look for new experiments that offers our students a “taste” of exploration of the real world, allow them to become familiar with biotechnology tools, and capture their attention, setting them on a path of discovery in our amazing world. The basis for this experiment is to have students identify the first filial generation (F1) plants from the parental types by screening for genetic variations between the three. SRAP uses primer pairs in PCR. By using a forward and reverse primer pairs that are 17 or 18 nucleotides long, SRAP can amplify open reading frames and test for the presence of polymorphism, or variations in the nucleotide sequences. This method is simpler andovercomes several problems with other PCR marker systems used to create genetic maps of plant species. Primers were originally created by Li and Quiros using the strategy of filler sequence, an open reading frame (ORF) region, and a selective, sequence. Starting atthe 5’ end of the forward primer bases 1-10 are filler and nonspecific; bases 11-14 are specific and use CCGG which targets exons in the plant chromosome; and bases 15-17 are selective. For the reverse primer bases 1-10 are filler (different than the forward primer filler); bases 11-14 are specific and use AATT which targets introns and promotor in the plant chromosome; and bases 15-17 are selective (Li and Quiros) . These primers enable the system to detect polymorphisms. This method can be applied to a rapid cycling version of Brassica rapa. Carolina Biological Supply company and University of Wisconsin-Madison teamed up to market a fast growing plant for use in the educational classroom. They call their system Wisconsin Fast Plants. These rapid-cycling brassicas were developed over a 15 year period by Professor Paul H. Williams. B. rapa plants are related to mustards and cabbages. The rapid-cycling brassicas are an excellent tool for classrooms because they take up little space, 2500 plants per square meter, grow from seed to flower in 18 days, and produce seed by day 28. All of this is accomplished using fluorescent lighting (Williams, P. H. ) . With the addition of rapid-cycling brassicas to our lab we felt we could develop a simple system whereby students could identify B. rapa plants with different traits. In fact, the goal was to find polymorphisms that would distinguish the two truebreeding B. rapa parents from their subsequent F1 offspring. To test this idea we recruited three of our biology students to test this project. Results Using primer pair combinations (Me1/Em1, Me4/Em1, Me4/Em3, Me4/Em6, Me5/Em6) the parental purple stem, parental non-purple stem and F1 purple stem plants were tested for polymorphisms. With the Wisconsin Fast plants we were able to get numerous bands, representing polymorphisms, from each of the three plants tested. Figures 1, 2, and 3 are DNA gels that show the banding patterns for each plant. Because we did not target one specific gene the F1 purple plant is not exactly the same banding pattern as the purple parent. This is reasonable because other genes were inherited from both parents. Primer pairs that worked well and gain di

FAQs

What is the main goal of this Brassica rapa DNA fingerprinting experiment?

To help students rapidly identify parental types (purple stem vs non-purple stem) and the F1 generation using SRAP-based detection of genetic variation.

How does SRAP contribute to detecting polymorphism in this experiment?

SRAP uses primer pairs in PCR to amplify sequence regions, producing band patterns that reflect polymorphisms in the nucleotide sequences.

What did the results show about distinguishing parental and F1 plants?

The method produced numerous bands from all three plant types, and selected primer pairs yielded banding patterns indicating polymorphisms for the parental and F1 samples in a classroom-suitable workflow.

Oct 15, 2026

Uploaded by Bulrr