Mapping quantitative trait loci for tissue culture response in VCS3M-DH population of Brassica rapa
Seo, M.S. ; Jin, M. ; Lee, S.S. ; Kwon, S.J. ; Mun, J.H. ; Park, B.S. ; Visser, R.G.F. ; Bonnema, A.B. ; Sohn, S.H. - \ 2013
Plant Cell Reports 32 (2013)8. - ISSN 0721-7714 - p. 1251 - 1261.
hordeum-vulgare l - shoot regeneration - cotyledonary explants - plant-regeneration - genetic-analysis - auxin receptor - ssp pekinensis - qtls - identification - rice
Quantitative trait loci (QTL) controlling callus induction and plant regeneration were identified in the VCS3M-DH population of Brassica rapa. The VCS3M-DH population showed wide and continuous variation in callus induction and shoot regeneration. Significant coefficient correlations were detected between these two parameters. Broad-sense heritability (h2) for the two traits was around 0.7, indicating genetic regulation of regeneration ability in this population. In the composite interval mapping analysis, two QTLs for callus induction ability, qCi2 and qCi7, were mapped on chromosome A02 and A07, explaining 28.6 % of phenotypic variation. For plant regeneration, four QTLs, qPr6-1 qPr6-2, qPr7, and qPr9 were identified on chromosome A06, A07, and A09, which in total explained 50.1 % of phenotypic variation. Furthermore, 15 putative candidate genes were found on the interval of the six QTLs, which were related to various plant hormones, MADS-box genes, and serine/threonine related genes. These results provide important information to identify genes related to tissue culture ability in B. rapa
Basal host resistance of barley to powdery mildew: connecting quantitative trait loci and candidate genes
Aghnoum, R. ; Marcel, T.C. ; Johrde, A. ; Pecchioni, N. ; Schweizer, P. ; Niks, R.E. - \ 2010
Molecular Plant-Microbe Interactions 23 (2010)1. - ISSN 0894-0282 - p. 91 - 102.
heterologous rust fungi - head blight resistance - defense-related genes - hordeum-vulgare l - pisum-sativum l. - disease-resistance - leaf rust - nonhost resistance - puccinia-hordei - spring barley
The basal resistance of barley to powdery mildew (Blumeria graminis f. sp. hordei) is a quantitatively inherited trait that is based on nonhypersensitive mechanisms of defense. A functional genomic approach indicates that many plant candidate genes are involved in the defense against formation of fungal haustoria. It is not known which of these candidate genes have allelic variation that contributes to the natural variation in powdery mildew resistance, because many of them may be highly conserved within the barley species and may act downstream of the basal resistance reaction. Twenty-two expressed sequence tag or cDNA clone sequences that are likely to play a role in the barley-Blumeria interaction based on transcriptional profiling, gene silencing, or overexpression data, as well as mlo, Ror1, and Ror2, were mapped and considered candidate genes for contribution to basal resistance. We mapped the quantitative trait loci (QTL) for powdery mildew resistance in six mapping populations of barley at seedling and adult plant stages and developed an improved high-density integrated genetic map containing 6,990 markers for comparing QTL and candidate gene positions over mapping populations. We mapped 12 QTL at seedling stage and 13 QTL at adult plant stage, of which four were in common between the two developmental stages. Six of the candidate genes showed coincidence in their map positions with the QTL identified for basal resistance to powdery mildew. This co-localization justifies giving priority to those six candidate genes to validate them as being responsible for the phenotypic effects of the QTL for basal resistance
Genetic variability in duration of pre-heading phases and relationships with leaf appearance and tillering dynamics in a barley population.
Borràs, G. ; Romagosa, I. ; Eeuwijk, F.A. van; Slafer, G.A. - \ 2009
Field Crops Research 113 (2009)2. - ISSN 0378-4290 - p. 95 - 104.
hordeum-vulgare l - harsh mediterranean environments - controlling flowering time - increasing early vigor - stem elongation - spring barley - photoperiod sensitivity - apical development - agronomic traits - fertile florets
The stem elongation phase seems critical in yield potential determination in barley (Hordeum vulgare L.). Extending its duration, without modifying total time to anthesis, has been proposed as a promising breeding tool. A prerequisite for its use is that the duration of phases before and after jointing (that including leaf and spikelet initiation, LS, and that of stem elongation, SE) should be under different genetic control. In addition, little is known about the implications of changes in the duration of LS and SE upon other developmental traits which could affect other aspects of yield generation, such as phyllochron and tillering. Thus, the objectives of the present work were to study the genetic variability in LS and SE, in traits related to leaf appearance and tillering, as well as their relationships, in a double-haploid (DH) population derived from the cross Henni × Meltan. DH lines and both parents were studied in four field trials. Despite the similarity in development between parents, there was significant genetic variability in duration of both LS and SE (i.e. considerable transgressive segregation was observed), with no major genetic correlations found between them. Although some significant genetic correlations were found between duration of phases and leaf appearance and tillering traits, it has been shown that modifying the duration of LS does not necessarily imply concomitant changes in traits that could be important for an early expansion of the crop canopy (i.e. phyllochron, onset and rate of tillering).
Buthionine sulfoximine (BSO)-mediated improvement in cultured embryo quality in vitro entails changes in ascorbate metabolism, meristem development and embryo maturation
Stasolla, C. ; Belmonte, M.F. ; Tahir, M. ; Elhiti, M. ; Joosen, R.V.L. ; Maliepaard, C.A. ; Sharpe, A. ; Gjetvaj, B. ; Boutilier, K.A. - \ 2008
Planta 228 (2008)2. - ISSN 0032-0935 - p. 255 - 272.
spruce picea-glauca - plant-tissue culture - hordeum-vulgare l - somatic embryos - gene-expression - brassica-napus - molecular characterization - microspore embryogenesis - glutathione synthesis - argonaute family
Applications of buthionine sulfoximine (BSO), an inhibitor of GSH (reduced glutathione), which switches the cellular glutathione pool towards the oxidized form GSSG, positively influences embryo quality by improving the structure of the shoot apical meristem and promoting embryo maturation, both of which improve the post-embryonic performance of the embryos. To investigate the mechanisms underlying BSO-mediated improvement in embryo quality the transcript profiles of developing Brassica napus microspore-derived embryos cultured in the absence (control) or presence of BSO were analyzed using a 15,000-element B. napus oligo microarray. BSO applications induced major changes in transcript accumulation patterns, especially during the late phases of embryogenesis. BSO affected the transcription and activities of key enzymes involved in ascorbate metabolism, which resulted in major fluctuations in cellular ascorbate levels. These changes were related to morphological characteristics of the embryos and their post-embryonic performance. BSO applications also activated many genes controlling meristem formation and function, including ZWILLE, SHOOTMERISTEMLESS, and ARGONAUTE 1. Increased expression of these genes may contribute to the improved structural quality of the shoot poles observed in the presence of BSO. Compared to their control counterparts, middle- and late-stage BSO-treated embryos also showed increased accumulation of transcripts associated with the maturation phase of zygotic embryo development, including genes encoding ABA-responsive proteins and storage- and late-embryogenic abundant (LEA) proteins. Overall these transcriptional changes support the observation that the BSO-induced oxidized glutathione redox state allows cultured embryos to reach both morphological and physiological maturity, which in turn guarantees successful regeneration and enhanced post-embryonic growth
Identification of QTLs for powdery mildew and scald resistance in barley
Shtaya, M.J.Y. ; Marcel, T.C. ; Sillero, J.C. ; Niks, R.E. ; Rubiales, D. - \ 2006
Euphytica 151 (2006)3. - ISSN 0014-2336 - p. 421 - 429.
quantitative trait loci - hordeum-vulgare l - erysiphe-graminis-hordei - rust puccinia-hordei - f-sp hordei - rhynchosporium-secalis - spring barley - ssp spontaneum - rflp markers - wild barley
A population of 103 recombinant inbred lines (RILs, F9-derived lines) developed from the two-row spring barley cross L94 × `Vada¿ was evaluated under field conditions for resistance against powdery mildew (Blumeria graminis f.sp. hordei) and scald (Rhynchosporium secalis). Apart from the major resistance gene mlo on chromosome 4 (4H), three QTLs (Rbgq1, Rbgq2 and Rbgq3) for resistance against powdery mildew were detected on chromosomes 2 (2H), 3 (3H), and 7 (5H), respectively. Rbgq1 and Rbgq2 have not been reported before, and did not map to a chromosome region where a major gene for powdery mildew had been reported. Four QTLs (Rrsq1, Rrsq2, Rrsq3 and Rrsq4) for resistance against scald were detected on chromosomes 3 (3H), 4 (4H) and 6 (6H). All four mapped to places where QTLs for scald resistance had been reported before in different populations