Variation in pinto seed coat darkening

Non-Peer ReviewedDarkening of the seed coat is a significant economic problem in pinto bean production. Beans that have darkened are considered old, more difficult to cook, and prices are discounted. Some varieties darken much more quickly than others and, as a result, are more often downgraded than those that retain their bright background colour. On a Pulse Canada marketing mission to Mexico in April 2002, all pinto bean buyers consistently identified the sample with the brightest background as their preference. They complained about the quality of pintos coming out of the Midwest USA and the eastern Prairies, primarily due to the darkened seed coats. We grew 10 different pinto varieties in four different environments and subjected the harvested beans to aging to determine the level of variability for seed coat darkening in the varieties. Varieties that maintain their bright background will be used in future breeding efforts to develop non-darkening pinto varieties

Flat pulses in a flat land – what’s on the horizon?

Non-Peer Reviewe

The age of 47Tuc from self-consistent isochrone fits to colour-magnitude diagrams and the eclipsing member V69

Our aim is to derive a self-consistent age, distance and composition for the globular cluster $47\,$Tucanae ($47\,$Tuc; NGC104). First, we reevaluate the reddening towards the cluster resulting in a nominal $E(B-V)=0.03\pm0.01$ as the best estimate. The $T_{\rm eff}$ of the components of the eclipsing binary member V69 is found to be $5900\pm72$ K from both photometric and spectroscopic evidence. This yields a true distance modulus $(m-M)_0=13.21\pm0.06$(random)$\pm0.03$(systematic) to $47\,$Tuc when combined with existing measurements of V69 radii and luminosity ratio. We then present a new completely self-consistent isochrone fitting method to ground based and $\textit{HST}$ cluster colour-magnitude diagrams and the eclipsing binary member V69. The analysis suggests that the composition of V69, and by extension one of the populations of $47\,$Tuc, is given by [Fe/H]$\sim-0.70$, [O/Fe]$\sim+0.60$, and $Y\sim0.250$ on the solar abundance scale of Asplund, Grevesse & Sauval. However, this depends on the accuracy of the model $T_{\rm eff}$ scale which is 50-75 K cooler than our best estimate but within measurement uncertainties. Our best estimate of the age of $47\,$Tuc is 11.8 Gyr, with firm ($3 \sigma$) lower and upper limits of 10.4 and 13.4 Gyr, respectively, in satisfactory agreement with the age derived from the white dwarf cooling sequence if our determination of the distance modulus is adopted.Comment: 19 pages, 8 figures, accepted for publication in MNRA

Do you eat the red ones last? Breeding new classes of coloured beans for adaptation to Saskatchewan

Non-Peer Reviewe

Seed size in lentil: iMapping at the U of S

Non-Peer Reviewe

Industrial hemp: agronomic fundamentals

Non-Peer Reviewe

Seed size in lentil: iMapping at the U of S

Non-Peer Reviewe

Age and helium content of the open cluster NGC 6791 from multiple eclipsing binary members. I. Measurements, methods, and first results

Earlier measurements of the masses and radii of the detached eclipsing binary V20 in the open cluster NGC 6791 were accurate enough to demonstrate that there are significant differences between current stellar models. Here we improve on those results and add measurements of two additional detached eclipsing binaries, the cluster members V18 and V80. The enlarged sample sets much tighter constraints on the properties of stellar models than has hitherto been possible, thereby improving both the accuracy and precision of the cluster age. We employed (i) high-resolution UVES spectroscopy of V18, V20 and V80 to determine their spectroscopic effective temperatures, [Fe/H] values, and spectroscopic orbital elements, and (ii) time-series photometry from the Nordic Optical Telescope to obtain the photometric elements. The masses and radii of the V18 and V20 components are found to high accuracy, with errors on the masses in the range 0.27-0.36% and errors on the radii in the range 0.61-0.92%. V80 is found to be magnetically active, and more observations are needed to determine its parameters accurately. The metallicity of NGC 6791 is measured from disentangled spectra of the binaries and a few single stars to be [Fe/H]= +0.29 \pm 0.03 (random) \pm 0.07 (systematic). The cluster reddening and apparent distance modulus are found to be E(B - V) = 0.160 \pm 0.025 and (m - M)V = 13.51 \pm 0.06 . A first model comparison shows that we can constrain the helium content of the NGC 6791 stars, and thus reach a more accurate age than previously possible. It may be possible to constrain additional parameters, in particular the C, N, and O abundances. This will be investigated in paper II.Comment: Accepted for publication in A&

Seed coat colour development in black beans

Non-Peer ReviewedDry beans come in a wide variety of seed coat patterns and colours and the quality and value of the bean crop is largely determined by appearance and condition of the seed, particularly colour uniformity and stability. In western Canada, black bean is a significant portion of the crop. For some black bean varieties, the seed coat colour does not fully develop until the pod is mature. This may be the result of genotype, or environment, or both. In these cases, harvesting at plant maturity rather than at seed maturity can lead to a non-uniform crop sample in which the black beans are mixed with beans that have a purple or gray tinge. Full expression of seed coat colour is economically important as variable colour development may result in a 2-4 cent per pound discount. Seed coat colour is determined by the presence of anthocyanins and condensed tannins. In this experiment, we examined the timing of pigment deposition in the seed coat in relation to pod maturity for 5 black bean varieties (CDC Expresso, CDC Nighthawk, CDC Jet, AC Black Diamond, and T39) to determine if there is genetic variation for timing of seed coat colour development. If it is under genetic control, we will be able to breed for earlier colour development to ensure full colour expression at plant maturity