Screening interspecific hybrids of Populus (P. ciliata × maximowiczii) using AFLP markers

Abstract

Hybrids of Populus ciliata x maximowiczii are very vigorous and outperform both the parents in growth performance and yield. Genetic evaluation of 24 of these interspecific hybrids along with the two mother trees ( Populus ciliata), and five male-parent ( Populus maximowiczii) genotypes was carried out using the AFLP marker assay. Eight AFLP primer combinations detected 428 markers, of which 280 (66%) were polymorphic. Genetic relationships within the samples were evaluated by generating the similarity matrix based on Jaccard's coefficient. The phenetic dendrograms, as well as the PCO plots, separated the hybrids and the two parent species into three distinct clusters. The hybrids grouped closer to the P. ciliata (female parent) cluster as compared to the P. maximowiczii (male parent) cluster. The hybrid cluster contained internal groupings, which correlated to some extent with growth performance. The four best performing hybrids (42m1, 65m1, 23m2, Cm2-5-20/91) formed a distinct sub-cluster. Data from a single primer combination was sufficient for distinguishing the hybrids from the parents and assigning paternity. The hybrids showed 22 markers that were absent in P. ciliata but were monomorphically present in all the hybrids, suggesting outcrossing and common paternity. Further, these 22 markers were found in all the P. maximowiczii genotypes confirming it as the male parent. These male-specific markers can be converted to SCAR markers and used for rapid screening of the P.ciliata x maximowiczii hybrids. The primer combination E-AAC x M-CAA was identified as most suitable for ascertaining true hybridity. AFLP proves to be a useful tool for screening of P. ciliata x maximowiczii hybrids at the early stages of development.

Application of amplified fragment length polymorphisms markers to study the hybridization between Pinus sibirica and P. pumila

“…Perhaps this is normal for hybrids. For example, AFLP analysis of hybrids between Populus ciliata and P. maximowiczii showed more asymmetry and considerable shift of hybrids to one of the parental species on PCoA scatter plot (Chauhan et al 2004). The observed asymmetry is probably associated with differentiated survival of different genotypes.…”

ISSR and AFLP identification and genetic relationships of Chinese elite accessions from the genusPopulus

“…It is an efficient and reliable genetic molecular marker technique that detects a much higher number of polymorphisms per reaction than that revealed by RFLP, RAPD or SSR assay [21,23] has been successfully applied to many kinds of plants such as rice [18], wheat [3], vetch [22], tea [2] and larch [30]. In poplar AFLP has been used to assess genetic diversity [32], screen interspecific hybrids [6], determine the genetic structure of natural populations [1] and construct genetic linkage maps [37].…”

Characterization of intergeneric hybrids of Erianthus rockii and Saccharum using molecular markers

“…The genus-specific bands contributed towards the differentiation of genotypes into the three main clusters seen in the dendrogram and the PCA analysis. This clustering has been seen with genus-specific bands in papaya (Van Droogenbroeck et al 2002) and species-specific bands in Populus hybrids (Chauhan et al 2004). This study also identified genetic variation among the hybrids.…”

“…Molecular markers and in particular AFLPs have been shown to be very effective in identifying true interspecific hybrids in Populus (Chauhan et al 2004) and Bromus (Ferdinandez and Coulman 2002). The primer combinations tested could uniquely fingerprint all the hybrids.…”

“…Morphological methods of hybrid identification in sugarcane are unreliable because it is difficult to differentiate the genuine hybrids from selfed progeny or progeny arising from pollen contamination (D'Hont et al 1995). AFLP markers have proved to be a valuable tool in evaluating hybrids in a number of species (Krauss 2000;Chauhan et al 2004). They have also been used to estimate selfing rates as all outcrossing events can be detected (Van Toai et al 1996).…”