Authors:A. Sabouri, M. Toorchi, B. Rabiei, S. Aharizad, A. Moumeni, and R. Singh
L.) is one of the most important crops in the world, especially Asian countries. Genetics of important traits in rice for yield improvement have always been a major breeding objective. Agronomic traits are inherited quantitatively, so quantitative trait loci (QTL) mapping for the potential use of molecular markers would be very helpful to plant breeders in developing improved rice varieties. In this investigation, a SSR linkage map of 1440.7cM of rice was constructed using 105 polymorphic simple sequence repeat (SSR) markers. The mapping population of 236 F
families derived from the cross of two rice varieties (Gharib × Sepidroud) was used for QTL mapping of agronomic traits. As many as 38 QTLs were detected to be associated with agronomic characteristics; some of them are being reported for the first time. The identified QTLs on specific chromosome regions explaining high phenotypic variance could be considered to use in marker-assisted selection (MAS) programs.
Authors:Z. Wang, L. Láng, A. Uhrin, O. Veisz, S. Liu, and G. Vida
The presence and frequency of the resistance gene complex
was investigated in the wheat breeding programme of the Agricultural Research Institute, Martonvásár, Hungary. A total of 226 wheat cultivars and advanced lines from Hungary and other countries were tested with an STS marker,
, to understand the distribution of the
resistance gene complex. A 150-bp PCR fragment was amplified in 64 wheat cultivars and lines with the resistance genes
, while a 229-bp fragment was detected in 162 genotypes without
. The genotypes with
accounted for 28.3% of the wheat cultivars and advanced lines tested. Among the 128 varieties and breeding lines of Martonvásár origin tested, 34 carried the
genes, with a frequency of 26.6%. The frequency of these genes was 30.6% in genotypes of other origin. The STS marker
could be used as an effective tool for the marker-assisted selection of
genes in breeding wheat cultivars with durable rust resistance.
Almond [Prunus dulcis (Mill.) D.A. Webb.] is cultivated for its nuts and is one of the oldest domesticated plants. Due to the genetically controlled self-incompatibility system that operates in this species, almond is characterized by great genetic diversity, the estimation of which has benefited from a range of marker techniques, including morphological characteristics, isoenzyme detection and molecular markers. Among the DNA-based molecular markers, simple sequence repeats (SSR) have been used most widely, although analyses have ranged from restriction fragment length polymorphism to the most recent single nucleotide polymorphism detection methods. Molecular markers have also been used to trace specific agronomic traits, e.g. self-(in)compatibility or kernel bitterness. Genetic diversity studies in almond have not revealed a direct relationship between the level of diversity and the origin of the germplasm. This might be explained by the relatively recent occurrence of self-compatibility in almond, which has not yet caused a serious loss of genetic diversity. The markers reviewed will be useful in monitoring and maintaining genetic diversity in almond breeding programmes, while others may permit marker-assisted selection for favourable agronomic traits. The cultivation, breeding and conservation of wild-growing almonds may equally benefit from the genetic diversity studies (especially those applying molecular markers).