Aerial high-throughput phenotyping of peanut leaf area index and lateral growth

Leaf area index (LAI) is the ratio of the total one-sided leaf area to the ground area, whereas lateral growth (LG) is the measure of canopy expansion. They are indicators for light capture, plant growth, and yield. Although LAI and LG can be directly measured, this is time consuming. Healthy leaves absorb in the blue and red, and reflect in the green regions of the electromagnetic spectrum. Aerial high-throughput phenotyping (HTP) may enable rapid acquisition of LAI and LG from leaf reflectance in these regions. In this paper, we report novel models to estimate peanut (Arachis hypogaea L.) LAI and LG from vegetation indices (VIs) derived relatively fast and inexpensively from the red, green, and blue (RGB) leaf reflectance collected with an unmanned aerial vehicle (UAV). In addition, we evaluate the models’ suitability to identify phenotypic variation for LAI and LG and predict pod yield from early season estimated LAI and LG. The study included 18 peanut genotypes for model training in 2017, and 8 genotypes for model validation in 2019. The VIs included the blue green index (BGI), red-green ratio (RGR), normalized plant pigment ratio (NPPR), normalized green red difference index (NGRDI), normalized chlorophyll pigment index (NCPI), and plant pigment ratio (PPR). The models used multiple linear and artificial neural network (ANN) regression, and their predictive accuracy ranged from 84 to 97%, depending on the VIs combinations used in the models. The results concluded that the new models were time- and cost-effective for estimation of LAI and LG, and accessible for use in phenotypic selection of peanuts with desirable LAI, LG and pod yield.

Effects of calcium-containing natural fertilizer on Camellia sinensis (L.) Kuntze

The effects of application of calcium-containing natural fertilizer on the functional state of the tea plant were studied. Application of calcium resulted weakening of the negative effects of high temperatures and water deficiency due to an increase in its heat resistance (on average by 30 - 40%), an increase in catalase activity (on average 5 - 10 %), as well as adaptive rearrangement of pigment ratio to increasing the content of carotenoids, chlorophylls and the their functional activity. In general, the more efficient functioning of the signaling intracellular network due to the calcium application provided better adaptability of plants to extreme conditions and more efficient recovery after subsequent rehydration, which in a whole contributed to an increase in shoot growth activity (on average 20%) and an increase in yield by an average of 27 - 33%.

Improvement of Anthocyanin Stability in Butterfly Pea Flower Extract by Co-pigmentation with Catechin

Most of the food processing operations involve the use of heat which generally causes alteration, and degradation of natural pigments, resulting in lower stability. One of the stability enhancement methods is co-pigmentation. This study aimed to determine effect of catechin co-pigment on stability of anthocyanins in Clitoria ternatea (or butterfly pea flower) extract. Degradation kinetics of anthocyanins in the extract were evaluated at three temperatures (28, 60, and 90℃). The effect of co-pigment ratio (catechin: anthocyanins at 1:1, 50:1 and 100:1 by weight) on the stability of anthocyanin extract at 90℃ was determined by the pH differential method. It was found that anthocyanin degradation followed the zero- order kinetics at all temperatures; the degradation rate increased as the temperature increased. At a lower pH, anthocyanins became more stable. An increase in the co-pigment ratio significantly retarded the degradation anthocyanins at 90℃. In addition, co-pigmentation also intensified the color of butterfly pea extract. The highest anthocyanin stability was obtained at co-pigment ratio of 100:1.

Hidden Reason of Paint System Delamination

In many instances paints interlayers delamination is attributed either to environmental or to application reasons. The composition as well as the structure, including morphology are always given for granted. Extended interlayer delamination was observed on two huge structures (>50000m2 each) causing more than $10 M damages. Overcoating time, UV exposure, Solvent retention and other possible environmental possible causes were considered. However, a careful morphological analysis showed that substantial differences existed in terms of the resin to pigment ratio, the surfactants, the quality of pigments and fillers (dimensions, shape, wettability, reactivity, homogeneity of distribution…) with respect to the sample used to certify suitability of the systems to climatic conditions C4 – C5 (ISO12944). The need to avoid any either voluntary or casual modification in both PVC and the kind and size of pigments to be used should be made evident as well as shown in some paragraph of existing Standards.

PHOTOSTABILITY OF PURPLE BACTERIAL LIGHT–HARVESTING COMPLEXES TOWARDS EXPOSURE OF LIGHT ILLUMINATION TRACED BY PIGMENT RATIO

Purple photosynthetic light–harvesting (LH2) is an attractive complex module for assembling hybrid nanostructures that feature energy transfer. LH2 has a broad absorption spectrum range from ultraviolet (UV) to near-infra red (NIR) region. Bacteriochlorophyll a molecules absorb at 320 nm to 400 nm (Soret band), 585 nm (Qx) and at NIR region (B800 and B850 bands), while carotenoid absorption bands span from 400 nm to 550 nm. LH2 has to be extracted from its native lipid bilayer membrane and placed in suitable matrix that less mobile and better adherent than the native lipid environment to determine its function. Previous results on pigment ratio determination in different strains of purple photosynthetic bacteria suggested a variation during initial log phase and late log phase. In this experiment, the goal is to reveal the behavior of pigment ratio in LH2 of Rhodopseudomonas palustris during irradiation of certain intensity of light. Photostability assay of LH2 from Rhodopseudomonas palustris in n-dodecyl-β-D-maltoside or DDM was determined under continuous illumination (3 000 μmol·m–2·s–1) for 300 min at room temperature by recording the absorption spectra. Degradation was observed in B850 and B800 at about 67 % and 64 %, respectively, as well as blue shift in B850. Initial pigments isolated from LH2 suggested a mixture of carotenoids and bacteriochlorophylls which was determined further using a high-performance liquid chromatography (HPLC).

Female mate preference explains countergradient variation in the sexual coloration of guppies ( Poecilia reticulata )

We tested the hypothesis that mate choice is responsible for countergradient variation in the sexual coloration of Trinidadian guppies ( Poecilia reticulata ). The nature of the countergradient pattern is that geographical variation in the carotenoid content of the orange spots of males is counterbalanced by genetic variation in drosopterin production, resulting in a relatively uniform pigment ratio. A female hue preference could produce this pattern, because hue is the axis of colour variation most directly affected by the pigment ratio. To test this hypothesis, we crossed two populations differing in drosopterin production and produced an F 2 generation with variable drosopterin levels. When the carotenoid content of the orange spots was held constant, female guppies preferred males with intermediate drosopterin levels. This shows that females do not simply prefer males with greater orange spot pigment content; instead, the ratio of the pigments also affects male attractiveness. To our knowledge, this is the first direct evidence for a hypothesized agent of countergradient sexual selection.