With the development of molecular marker technology in the 1980s, the fate of plant breeding has changed. Different types of molecular markers have been developed and advancement in sequencing technologies has geared crop improvement. To explore the knowledge about molecular markers, several reviews have been published in the last three decades; however, all these reviews were meant for researchers with advanced knowledge of molecular genetics. This review is intended to be a synopsis of recent developments in molecular markers and their applications in plant breeding and is devoted to early researchers with a little or no knowledge of molecular markers. The progress made in molecular plant breeding, genetics, genomic selection and genome editing has contributed to a more comprehensive understanding of molecular markers and provided deeper insights into the diversity available for crops and greatly complemented breeding stratagems. Genotyping-by-sequencing and association mapping based on next-generation sequencing technologies have facilitated the identification of novel genetic markers for complex and unstructured populations. Altogether, the history, the types of markers, their application in plant sciences and breeding, and some recent advancements in genomic selection and genome editing are discussed.

Turkey presents a great diversity of common bean landraces in farmers’ fields. We collected 183 common bean accessions from 19 different Turkish geographic regions and 5 scarlet runner bean accessions to investigate their genetic diversity and population structure using phenotypic information (growth habit, and seed weight, flower color, bracteole shape and size, pod shape and leaf shape and color), geographic provenance and 12,557 silicoDArT markers. A total of 24.14% markers were found novel. For the entire population (188 accessions), the expected heterozygosity was 0.078 and overall gene diversity, Fst and Fis were 0.14, 0.55 and 1, respectively. Using marker information, model-based structure, principal coordinate analysis (PCoA) and unweighted pair-group method with arithmetic means (UPGMA) algorithms clustered the 188 accessions into two main populations A (predominant) and B, and 5 unclassified genotypes, representing 3 meaningful heterotic groups for breeding purposes. Phenotypic information clearly distinguished these populations; population A and B, respectively, were bigger (>40g/100 seeds) and smaller (<40g/100 seeds) seed-sized. The unclassified population was pure and only contained climbing genotypes with 100 seed weight 2–3 times greater than populations A and B. Clustering was mainly based on A: seed weight, B: growth habit, C: geographical provinces and D: flower color. Mean kinship was generally low, but population B was more diverse than population A. Overall, a useful level of gene and genotypic diversity was observed in this work and can be used by the scientific community in breeding efforts to develop superior common bean strains.

Bu çalışma melez mısır ıslahında in-vivo katlanmış haploid hatların elde edilmesi çalışma s ında kullanılan farklı induzer genotiplerin haploid indirgeme oranlarının tespit edilmesi amacıyla 2014 yılında Doğu Akdeniz Tarımsal Araştırma Enstitüsü’nde yürütülmüştür. Çalışmada induzer olarak (haploid indirgeyici ve toz verici) olarak RWS, RWK-76 hatları ile bu hatların melezi olan RWS X RWK-76 melezi ve Stock-6 hattı kullanılmıştır. Haploid tohum elde etmek amacıyla ana (toz alıcı) olarak, toplamda 75 farklı genotip kullanılmıştır. Bunlardan 66’sını Doğu Akdeniz Tarımsal Araştırma Enstitüsü mısır ıslah çalışmaları kapsamında elde edilen F 2 kademesindekimateryal, 9’unu ise ticari hibrit çeşitlerin açıkta tozlanması ile elde edilen populasyonlardan seçilen 9 farklı genotip oluşturmuştur. Induzer olarak kullanılan genotiplerin haploid indirgeme oranları çalışmada ana (toz alıcı) olarak kullanılan genotiplere göre değişiklik göstermiştir. Ana olarak kullanılan 75 genotipten 69’undan toplam 1463 adet haploid tohum alınmıştır. Haploid tohumların seleksiyonu renk markörüne göre yapılmıştır. En yüksek haploid tohum oranı %7.80 ile induzer olarak kullanılan RWK-76 hattından elde edilmiştir. En düşük haploid tohum oranı ise %1.28 ile induzer Stock-6 hattından alınmıştır. Yapılan çalışmada ortalama haploid tohum elde etme oranı %4.79 olarak saptanmıştır.