Bolting tendency in the crop species Beta vulgaris, which includes sugar beet, is a complex trait governed by various environmental cues, including prolonged periods of cold temperatures over winter (vernalization) and photoperiod, and multiple genetic factors. Two loci which promote bolting in the absence of vernalization are known in beet, the major bolting locus B on chromosome II and the B2 locus on chromosome IX. Here, genetic linkage and quantitative trait locus analyses in two populations derived from a cross between a biennial genotype, which was identified in a phenotypic screen for EMS-induced bolting mutants and requires vernalization to bolt, and an annual wild beet accession revealed the presence of a novel major bolting locus B4 which is linked to the B locus but promotes annual bolting independently of B. The genetic distance between B and B4 on chromosome II is 11 cM. A sequence-based marker was identified which co-segregates with bolting behavior and co-localizes with the B4 locus.

Beta vulgaris is a facultative perennial species which exhibits large intraspecific variation in vernalization requirement and includes cultivated biennial forms such as the sugar beet. Vernalization requirement is under the genetic control of the bolting locus B on chromosome II. Previously, ethyl methanesulfonate (EMS) mutagenesis of an annual accession had yielded several mutants which require vernalization to bolt and behave as biennials. Here, five F2 populations derived from crosses between biennial mutants and annual beets were tested for co-segregation of bolting phenotypes with genotypic markers located at the B locus. One mutant appears to be mutated at the B locus, suggesting that an EMS-induced mutation of B can be sufficient to abolish annual bolting. Co-segregation analysis in four populations indicates that the genetic control of bolting also involves previously unknown major loci not linked to B, one of which also affects bolting time and was genetically mapped to chromosome IX.

The transition from vegetative growth to reproductive development is a complex process that requires an integrated response to multiple environmental cues and endogenous signals. In Arabidopsis thaliana, which has a facultative requirement for vernalization and long days, the genes of the autonomous pathway function as floral promoters by repressing the central repressor and vernalization-regulatory gene FLC. Environmental regulation by seasonal changes in daylength is under control of the photoperiod pathway and its key gene CO. The root and leaf crop species Beta vulgaris in the caryophyllid clade of core eudicots, which is only very distantly related to Arabidopsis, is an obligate long-day plant and includes forms with or without vernalization requirement. FLC and CO homologues with related functions in beet have been identified, but the presence of autonomous pathway genes which function in parallel to the vernalization and photoperiod pathways has not yet been reported. Here, this begins to be addressed by the identification and genetic mapping of full-length homologues of the RNA-regulatory gene FLK and the chromatin-regulatory genes FVE, LD, and LDL1. When overexpressed in A. thaliana, BvFLK accelerates bolting in the Col-0 background and fully complements the late-bolting phenotype of an flk mutant through repression of FLC. In contrast, complementation analysis of BvFVE1 and the presence of a putative paralogue in beet suggest evolutionary divergence of FVE homologues. It is further shown that BvFVE1, unlike FVE in Arabidopsis, is under circadian clock control. Together, the data provide first evidence for evolutionary conservation of components of the autonomous pathway in B. vulgaris, while also suggesting divergence or subfunctionalization of one gene. The results are likely to be of broader relevance because B. vulgaris expands the spectrum of evolutionarily diverse species which are subject to differential developmental and/or environmental regulation of floral transition.

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In order to assess efficiency of drought tolerance indices, 50 bread wheat genotypes were evaluated under three environments: normal (clay fertile soil, E1), 100% (E2), and 50% (E3) field water capacity in sandy calcareous soil. A total of 14 drought tolerance indices including grain yield/plant, grain yield/spike, 1000-kernel weight, spike length, no. of tillers, plant height, flowering time, stomata frequency, stomata width, stomata length, drought susceptibility index (DSI), stress tolerance index (STI), yield stability index (YSI), and harmonic mean (HM) were estimated. A moderate to high broad-sense heritability was obtained for 1000-kernel weight (0.47), spike length (0.38), plant height (0.54), flowering time (0.73), stomata frequency (0.59), and stomata length (0.54). Grain yield/plant was strongly positively correlated with grain yield/spike, no. of tillers, plant height, flowering time, stomata length, STI, YSI, and HM, while negatively correlated with stomata frequency and DSI in E2 and E3, respectively. Thus, highly heritable traits strongly correlated with grain yield under stress conditions especially stomata frequency and length could be used as reliable indices for selecting high-yielding genotypes tolerant to drought stress. Cluster analysis based on morpho-physiological traits suggested the group 3 genotypes in E2 as the most tolerant genotypes to be used for developing improved varieties.

The aim of this study was to investigate the range utilization of Rhode Island Red hens, grazing outdoor (under tropical conditions) and to scan their activities inside the house as well as during their outdoor visits. The activities of RIR hens, raised in indoor floor pens connected with outdoor areas covered with natural vegetation, were scanned and recorded individually within 15 minute intervals between 08:00 and 17:00 hours (37 scans a day) for a duration of twelve weeks. The results revealed that, 40.5% of the hens were observed to be on the range at each scanning time; where they engaged their outdoor visits in foraging (11.4%), exploring (8.62%), roaming (6.1%), standing (3.5%), primping (5.6%) and resting (5.4%). Besides, the utilization of the closest part of the range to the house was significantly the highest in comparison with the middle and farthest parts (73.0 vs. 24.9 and 2.1%, respectively), and the highest (P 0.05) average utilization of the range was recorded during the early day hours, versus the midday and late day hours. In total, 24 meters apart from the house forms the most adequate distance for free range RIR hens while longer distances would rarely be visited. The grazing RIR hens (in the tropics) utilized the outdoor area effectively and performed natural behavior.

This work examines the effect of the interaction between different concentrations of two cryoprotectants – glycerol (GLY) and dimethylacetamide (DMA) – and two methods of cryopreservation – pellets produced by plunging into liquid nitrogen and gradual in-straw freezing – on frozen/thawed chicken sperm variables. Sperm was cryopreserved using: (i) 6% DMA, following the in-straw and the pellet methods (ii) 11% GLY, following the in-straw and the pellet methods; and (iii) 8% GLY in the in-straw method and 3% DMA in the pellet method (i.e. reduced cryoprotectant concentrations). When 6% DMA was used as the cryoprotectant, no differences were seen between the in-straw and pellet methods in terms of frozen/thawed sperm variables or fertility (10.8% and 12.8%, respectively). The viability and motility variables of the frozen/ thawed sperm produced using the in-straw method with 11% GLY were higher (p 0.05) than those recorded for the sperm preserved using the same cryoprotectant and concentration in the pellet method. However, fertility was extremely low in both groups (2.1% and 4.2% for the in-straw and pellet methods, respectively). Finally, the use of 8% GLY in the in-straw method returned higher sperm viability, intact acrosome and motility values than the use of 3% DMA in the pellet method (p 0.01). No differences were seen, however, in the fertility results obtained (28.8% and 25.0%, respectively). These results suggest that cryoprotectant concentrations can be reduced and still provide acceptable fertility rates.