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An X-ray mutant showing an early flowering phenotype has been identified in einkorn wheat (Triticum monococcum L.), for which a major QTL for heading time was previously mapped in the telomeric region on the long arm of chromosome 3A. Recent advances in Triticeae genomics revealed that the gene order in this region is highly conserved between wheat and barley. Thus, we adopted a hypothetical gene order in barley, the so-called GenomeZipper, to develop DNA markers for fine mapping the target gene in wheat. We identified three genes tightly linked to the early heading phenotype. PCR analysis revealed that early-flowering is associated with the deletion of two genes in the mutant. Of the two deleted genes, one is an ortholog of the LUX ARRHYTHMO (LUX)/PHYTOCLOCK 1 (PCL1) gene found in Arabidopsis, which regulates the circadian clock and flowering time. We found distorted expression patterns of two clock genes (TOC1 and LHY) in the einkorn pcl1 deletion mutant as was reported for the Arabidopsis lux mutant. Transcript accumulation levels of photoperiod-response related genes, a photoperiod sensitivity gene (Ppd-1) and two wheat CONSTANS-like genes (WCO1 and TaHd1), were significantly higher in the einkorn wheat mutant. In addition, transcripts of the wheat florigen gene (WFT) accumulated temporally under shortday conditions in the einkorn wheat mutant. These results suggest that deletion of WPCL1 leads to abnormally higher expression of Ppd-1, resulting in the accumulation of WFT transcripts that triggers flowering even under short-day conditions. Our observations from gene mapping, gene deletions, and expression levels of flowering related genes strongly suggest that WPCL1 is the most likely candidate gene for controlling the early flowering phenotype in the einkorn wheat mutant.

and stem, wrinkly or nonwrinkly leaves, and a fragrance specific to var. crispa. Perilla frutescens (L.) Britton var. frutescens is extensively culti-Today P. frutescens var. frutescens is extensively cultivated on a large scale throughout the Korea, whereas var. crispa is vated and used in Korea (Nitta, 2001), although cultinot. The weedy types of both var. frutescens and var. crispa are ofvated var. frutescens probably originated in China (Maten found along roadsides, waste lands, and around farmers' fields. Although Perilla is one of the important leafy vegetable and oil crops kino, 1961). In Korea, var. frutescens is used not only in Korea, systematic analyses on its genetic structure have been limited as an oil crop but also as a vegetable crop. Recently, and are needed for future breeding progress. The objective of this accompanied by increased meat consumption and develstudy was to determine genetic diversity and relatedness in Korean opment of various cooking methods of fresh leaves, var. accessions of Perilla. Field surveys and amplified fragment length frutescens became one of the most important crops in polymorphism (AFLP) analyses were conducted to determine genetic Korea. However, modern breeding methods and sysdiversity. Analyses of 30 Perilla accessions by seven AFLP primer tematic introduction of germplasm have not been praccombinations identified a total of 121 fragments, of which 72 (60%) ticed widely on this crop in Korea. No cultivars have were polymorphic at the species level. Shanon's index of diversity Hs been developed solely for production as oil or vegetaof the AFLP variations for cultivated type of var. frutescens, weedy ble crop. type of var. frutescens, and weedy type of var. crispa were 0.63, 2.00, and 1.75, respectively. The weedy type of var. frutescens exhibited

Aims Because plants cannot change their environmental circumstances by changing their location, they must instead adapt to a wide variety of environmental conditions, especially soil conditions. One of the most effective ways for a plant to adapt to a given soil condition is by modifying its root system architecture. We aim to identify the genetic factors controlling root growth angle, a trait that affects root system architecture. Methods The present study consisted of a genetic analysis of the seminal root growth angle in wheat; the parental varieties of the doubled haploid lines (DHLs) used in this study exhibited significantly different root growth directions. Using the 'basket' method, the ratio of deep roots (DRR; the proportion of total roots with GA > 45 degrees) was observed for evaluating deep rooting. Results We were able to identify novel quantitative trait loci (QTLs) controlling the gravitropic and hydrotropic responses of wheat roots. Moreover, we detected one QTL for seminal root number per seedling (RN) on chromosome 5A and two QTLs for seminal root elongation rate (ER) on chromosomes 5D and 7D. Conclusions Gravitropic and hydrotropic responses of wheat roots, which play a significant role in establishing root system architecture, are controlled by independent genetic factors.

The complex process of allopolyploid speciation includes various mechanisms ranging from species crosses and hybrid genome doubling to genome alterations and the establishment of new allopolyploids as persisting natural entities. Currently, little is known about the genetic mechanisms that underlie hybrid genome doubling, despite the fact that natural allopolyploid formation is highly dependent on this phenomenon. We examined the genetic basis for the spontaneous genome doubling of triploid F1 hybrids between the direct ancestors of allohexaploid common wheat (Triticum aestivum L., AABBDD genome), namely Triticum turgidum L. (AABB genome) and Aegilops tauschii Coss. (DD genome). An Ae. tauschii intraspecific lineage that is closely related to the D genome of common wheat was identified by population-based analysis. Two representative accessions, one that produces a high-genome-doubling-frequency hybrid when crossed with a T . turgidum cultivar and the other that produces a low-genome-doubling-frequency hybrid with the same cultivar, were chosen from that lineage for further analyses. A series of investigations including fertility analysis, immunostaining, and quantitative trait locus (QTL) analysis showed that (1) production of functional unreduced gametes through nonreductional meiosis is an early step key to successful hybrid genome doubling, (2) first division restitution is one of the cytological mechanisms that cause meiotic nonreduction during the production of functional male unreduced gametes, and (3) six QTLs in the Ae . tauschii genome, most of which likely regulate nonreductional meiosis and its subsequent gamete production processes, are involved in hybrid genome doubling. Interlineage comparisons of Ae . tauschii ’s ability to cause hybrid genome doubling suggested an evolutionary model for the natural variation pattern of the trait in which non-deleterious mutations in six QTLs may have important roles. The findings of this study demonstrated that the genetic mechanisms for hybrid genome doubling could be studied based on the intrinsic natural variation that exists in the parental species.