Pre-harvest sprouting (PHS) is one of the serious problems for wheat production, especially in rainy regions. Although seed dormancy is the most critical trait for PHS resistance, the control of heading time should also be considered to prevent seed maturation during unfavorable conditions. In addition, awning is known to enhance water absorption by the spike, causing PHS. In this study, we conducted QTL analysis for three PHS resistant related traits, seed dormancy, heading time and awn length, by using recombinant inbred lines from 'Zenkouji-komugi' (high PHS resistance) × 'Chinese Spring' (weak PHS resistance). QTLs for seed dormancy were detected on chromosomes 1B (QDor-1B) and 4A (QDor-4A), in addition to a QTL on chromosome 3A, which was recently cloned as TaMFT-3A. In addition, the accumulation of the QTLs and their epistatic interactions contributed significantly to a higher level of dormancy. QDor-4A is co-located with the Hooded locus for awn development. Furthermore, an effective QTL, which confers early heading by the Zenkouji-komugi allele, was detected on the short arm of chromosome 7B, where the Vrn-B3 locus is located. Understanding the genetic architecture of traits associated with PHS resistance will facilitate the marker assisted selection to breed new varieties with higher PHS resistance.

Low or excessive soil fertility is a major constraint to potato production. The influence of each individual nutrient element on potato plants under field studies remains ambiguous due to the influence of environmental variations. Creating an in vitro model plant with deficient or excessive nutrient content will provide a more controlled study and allow for a better understanding of how the concentration of one element can affect the uptake of other elements. Here we designed a tissue culture-based nutrition control system to systematically analyze the effects of essential nutrients on potato plants. Insufficient or excessive nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) contents were created by modifying the Murashige and Skoog (MS) medium. Deficient to toxic plant nutrient statuses were successfully defined by the evaluation of dry biomass and morphological symptoms. The results showed that plant shoot growth, nutrient uptake and content, and nutrient interactions were all significantly impacted by the changes in the MS media nutrient concentrations. These tissue culture systems can be successfully used for further investigations of nutrient effects on potato production in response to biotic and abiotic stresses in vitro.

Pre-harvest sprouting frequently occurs in Triticum aestivum (wheat) and Hordeum vulgare (barley) at the end of the maturity period due to high rainfall, particularly in Asian monsoon areas. Seed dormancy is a major mechanism preventing pre-harvest sprouting in these crops. We identified orthologous sequences of the major Hordeum vulgare (barley) seed dormancy gene Qsd1 in hexaploid wheat cv. Chinese Spring by performing genomic clone sequencing, followed by transcript sequencing. We detected 13 non-synonymous amino acid substitutions among the three sub-genomes of wheat and found that the Qsd1 sequence in the B sub-genome is most similar to that in barley. The Qsd1 sequence in A genome diploid wheat is highly similar to that in the hexaploid A sub-genome. Wheat orthologs of Qsd1 showed closer similarities to barley Qsd1 than did those of other accessions in the DNA database. Like barley Qsd1, all three wheat Qsd1s showed embryo-specific gene expression patterns, indicating that barley and wheat Qsd1 share an orthologous origin. The alignment of four hexaploid wheat cultivars indicated that the amino acid sequences of three spring cultivars, Chinese Spring, Haruyo Koi, and Fielder, are exactly the same in each sub-genome. Only Kitahonami has three amino acid substitutions at the B sub-genome. Kitahonami has a longer seed dormancy period than does Chinese Spring. Sequence polymorphisms between Chiniese Spring and Kitahonami in the B sub-genome may underlie the phenotypic differences in seed dormancy between these hexaploid wheat cultivars.

Spelt wheat (Triticum aestivum subsp. spelta), a subspecies of common wheat, is a genetic resource for the breeding of bread wheat (T. aestivum subsp. aestivum); however, genetic analyses of agronomic traits in bread wheat × spelt crosses are insufficient. Here, we conducted QTL analysis in the recombinant inbred lines from a bread wheat × spelt cross. In addition to the major Q locus, QSpd.obu-4D was detected with the spelt allele conferring a higher spikelet density than the bread wheat allele. The effect of QSpd.obu-4D was evident in the presence of the Q allele of bread wheat, suggesting that this variation might be cryptic in spelt wheat with the q allele. Two QTLs with stable effects were identified for grain length, one of which (QGl.obu-1A) has never been detected in a bread wheat × spelt cross. The spelt wheat allele at QHt.obu-7B conferring later heading was identified in the Vrn-B3 region and could be a novel gene source for modifying heading time. Furthermore, QGi.obu-2B, responsible for low grain dormancy of spelt wheat, was detected. Further exploration and identification of useful QTLs could accelerate the utilization of spelt wheat as a genetic resource for bread wheat breeding programs.