Fine-mapping of qRL6.1, a major QTL for root length of rice seedlings grown under a wide range of NH4+ concentrations in hydroponic conditions

Root system development is an important target for improving yield in cereal crops. Active root systems that can take up nutrients more efficiently are essential for enhancing grain yield. In this study, we attempted to identify quantitative trait loci (QTL) involved in root system development by measuring root length of rice seedlings grown in hydroponic culture. Reliable growth conditions for estimating the root length were first established to renew nutrient solutions daily and supply NH4+ as a single nitrogen source. Thirty-eight chromosome segment substitution lines derived from a cross between ‘Koshihikari’, a japonica variety, and ‘Kasalath’, an indica variety, were used to detect QTL for seminal root length of seedlings grown in 5 or 500 μM NH4+. Eight chromosomal regions were found to be involved in root elongation. Among them, the most effective QTL was detected on a ‘Kasalath’ segment of SL-218, which was localized to the long-arm of chromosome 6. The ‘Kasalath’ allele at this QTL, qRL6.1, greatly promoted root elongation under all NH4+ concentrations tested. The genetic effect of this QTL was confirmed by analysis of the near-isogenic line (NIL) qRL6.1. The seminal root length of the NIL was 13.5–21.1% longer than that of ‘Koshihikari’ under different NH4+ concentrations. Toward our goal of applying qRL6.1 in a molecular breeding program to enhance rice yield, a candidate genomic region of qRL6.1 was delimited within a 337 kb region in the ‘Nipponbare’ genome by means of progeny testing of F2 plants/F3 lines derived from a cross between SL-218 and ‘Koshihikari’

Gene and QTL detection in a three-way barley cross under selection by a mixed model with kinship information using SNPs

Quantitative trait locus (QTL) detection is commonly performed by analysis of designed segregating populations derived from two inbred parental lines, where absence of selection, mutation and genetic drift is assumed. Even for designed populations, selection cannot always be avoided, with as consequence varying correlation between genotypes instead of uniform correlation. Akin to linkage disequilibrium mapping, ignoring this type of genetic relatedness will increase the rate of false-positives. In this paper, we advocate using mixed models including genetic relatedness, or ‘kinship’ information for QTL detection in populations where selection forces operated. We demonstrate our case with a three-way barley cross, designed to segregate for dwarfing, vernalization and spike morphology genes, in which selection occurred. The population of 161 inbred lines was screened with 1,536 single nucleotide polymorphisms (SNPs), and used for gene and QTL detection. The coefficient of coancestry matrix was estimated based on the SNPs and imposed to structure the distribution of random genotypic effects. The model incorporating kinship, coancestry, information was consistently superior to the one without kinship (according to the Akaike information criterion). We show, for three traits, that ignoring the coancestry information results in an unrealistically high number of marker–trait associations, without providing clear conclusions about QTL locations. We used a number of widely recognized dwarfing and vernalization genes known to segregate in the studied population as landmarks or references to assess the agreement of the mapping results with a priori candidate gene expectations. Additional QTLs to the major genes were detected for all traits as well

Protection of Animals against Cruelty: Transport of Cattle, Sheep, Goats and Pigs

The inspections carried out by the officers of the State Veterinary Administration (SVA) within the framework of surveillance of animal transport revealed that cases of violation of the principles of animal protection may and do occur. Therefore evaluation was made of transport in selected groups of cattle, sheep, goats and pigs in the Czech Republic during the period of 1996 to 2001. Each inspection was assessed using the following scale: (1) animal protection requirements fulfilled, (2) animal protection requirements partially fulfilled and veterinary measures for the improvement of animal protection imposed, (3) failure to fulfil animal protection requirements. The proportion of the situations of when animal protection requirements were partially met and veterinary measures were imposed to improve the level of protection in cattle varied between 0.00 % and 1.35 % of the total number of the inspections carried out. In sheep and goats this situation occurred only sporadically. In pigs the proportion was 0.22 % to 2.22 % of the total number of the inspections carried out. The proportion of the situations when failure to fulfil animal protection requirements in cattle occurred varied between 0.00 % and 0.83 % of the total number of the inspections carried out. In sheep this situation occurred in a single case only and in goats no such situation was recorded. In pigs the same proportion varied between 0.00 % and 3.31%. W

Comparison of breeding methods for forage yield in red clover

Three methods of red clover (Trifolium pratense L.) breeding for forage yield in two harvest years on locations in Bredelokke (Denmark), Hladké Životice (Czech Republic) and Les Alleuds (France) were compared. Three types of 46 candivars1, developed by A) recurrent selection in subsequent generations (37 candivars, divided into early and late group), B) polycross progenies (4 candivars) and C) ge­no-phe­no­ty­pic selection (5 candivars) were compared. The trials were sown in 2005 and cut three times in 2006 and 2007; their evaluation is based primarily on total yield of dry matter. The candivars developed by polycross and geno-phenotypic selections gave significantly higher yields than candivars from the recurrent selection. However, the candivars developed by the methods B and C did not differ significantly. The candivars developed by these progressive methods were suitable for higher yielding and drier environment in Hladké Životice (where was the highest yield level even if averaged annual precipitation were lower by 73 and 113 mm in comparison to other locations, respectively); here was ave­ra­ge yield higher by 19 and 13% for B and C in comparison to A method. Highly significant interaction of the candivars with locations was found. It can be concluded that varieties specifically aimed to different locations by the methods B and C should be bred; also the parental entries should be selected there