Characterization of Filbert (Corylus) Species and Cultivars Using Gradient Polyacrylamide Gel Electrophoresis

Abstract

A chemical identification procedure previously used to identify apple and pear species, cultivars and clonal accessions, was tried with Corylus (filbert, hazel) species, cultivars and clonal accessions. Following electrophoresis, the peroxidase, phenol oxidase, and acid phosphatase isozyme patterns on anionic polyacrylamide gradient gels were determined. These patterns were found to vary between clonal accessions, but did not change, within a given accession during and following the test period (May through October). Thus, these patterns were considered to represent genetic characteristics suitable for identification purposes. The patterns were used to identify 78 Corylus accessions at the National Clonal Germplasm Repository Corvallis, Oregon. All accessions tested (species, cultivars and clones) were distinguishable using this system. The diversity of isozyme patterns was greater in Corylus than Pyrus populations previously sampled. This technique appears to have the potential to readily identify filbert accessions and could be an important aid in the characterization of germplasm material.

Characterization of Quince (Cydonia) Cultivars Using Polyacrylamide Gel Electrophoresis

“…In previous investigations of other genera [Corylus (1), Malus (20,23), Pyrus (8,21,22)] isozyme patterns that identified each clone remained constant throughout the year, and were not affected by the age of the plant from which the shoots were collected. This is attributed to the diversity of tissues found in stems, which not only include phloem, xylem and cambium, but also photosynthetic, active tis sues (7).…”

“…Figure 3 utilizes data for Cydonia and that of a pool of cultivars of Malus (taken from Table 2 of reference 23) to develop estimates of clonal diversity by probit plot methods (1,10,22). What the probit plot does in this application is give a number and a rationale for what is intuitively per ceived: 'if a small number of patterns is found in a sample of a population, then the number of total patterns in that population is also small' (P. Breen, pers.…”

“…Probit analysis is used to determine values at zero input of a variable (1,10,22). This is done using a probit scale that (linearizes) the normal distribution of a population.…”

“…This permits the determination of data at zero input of a variable by linear extrapolation of data taken at known values of the variable. This method is conlmonly perfornled graphically (using 'probit' graph paper) (1,22), although it can also be done mathematically (10). In this use the coordinates are: Y-axis linear, X -axis probit scale.…”

“…Chemical identification (fingerprinting) of plant species and cultivars has received increased attention (1,3,4,5,6,8,11,13,18,20,21,23,24,30,31) from plant breeders, the nursery industry, growers, and U. S. trade officials (1) because of the increased recognition of germplasm reserves and the importance of exact clonal identification. The Na tional Clonal Germplasm Repository (NCGR) system, col lects, maintains, identifies and characterizes clones of selected crop genera (16).…”