GGE BIPLOT ANALYSIS OF YIELD STABI LITY FOR ANDEAN DRY BEAN ACCESSIONS GROWN UNDER DIFFERENT ABIOTIC STRESS REGIMES IN TANZANIA

Large seeded Andean dry beans (Phaseolus vulgaris L.) are most preferred in Africa. However, low soil fertility and increasing drought stress conditions due to climate change are among the challenges faced by farmers in this region. The purpose of this study was to identify Andean genotypes with yield stability and to identify the best environments for selection of this trait. GGE-Biplot analysis was used to examine 183 Andean bean genotypes in Tanzania. Results indicated significant environment (E), genotype (G) and genotype x environment (GE) effects for seed yield. The environment explained 46%, genotype 20%, and GE 34% of the total (G + E + GE) variation. Two principal components explained 41.21% (PC1) and 26.35% (PC2) of GGE sum of squares. The Andean genotypes, ADP-102 (Jessica)- purple mottle, large seed, bush plant habit, released by Selian Agriculture Research Institution (ARI) in Tanzania; ADP-220 (G5625)- red, large seed, vine plant habit, from Central America; ADP-276 (G13654) - brown, medium seed, vine, from Mexico; and ADP-648 (‘Red Kloud’) large red kidney, with bush plant habit, were stable across environments and can be recommended for general adaptation across environments. An individual location for selection for yield stability was not identified, thus justifying the continued need for multiple test sites

GGE BIPLOT ANALYSIS OF YIELD STABI LITY FOR ANDEAN DRY BEAN ACCESSIONS GROWN UNDER DIFFERENT ABIOTIC STRESS REGIMES IN TANZANIA

Large seeded Andean dry beans (Phaseolus vulgaris L.) are most preferred in Africa. However, low soil fertility and increasing drought stress conditions due to climate change are among the challenges faced by farmers in this region. The purpose of this study was to identify Andean genotypes with yield stability and to identify the best environments for selection of this trait. GGE-Biplot analysis was used to examine 183 Andean bean genotypes in Tanzania. Results indicated significant environment (E), genotype (G) and genotype x environment (GE) effects for seed yield. The environment explained 46%, genotype 20%, and GE 34% of the total (G + E + GE) variation. Two principal components explained 41.21% (PC1) and 26.35% (PC2) of GGE sum of squares. The Andean genotypes, ADP-102 (Jessica)- purple mottle, large seed, bush plant habit, released by Selian Agriculture Research Institution (ARI) in Tanzania; ADP-220 (G5625)- red, large seed, vine plant habit, from Central America; ADP-276 (G13654) - brown, medium seed, vine, from Mexico; and ADP-648 (‘Red Kloud’) large red kidney, with bush plant habit, were stable across environments and can be recommended for general adaptation across environments. An individual location for selection for yield stability was not identified, thus justifying the continued need for multiple test sites

Unusual features in the nonlinear microwave surface impedance of Y-Ba-Cu-O thin films

Striking features have been found in the nonlinear microwave (8 GHz) surface impedance $Z_s=R_s + jX_s$ of high-quality YBaCuO thin films with comparable low power characteristics [$R_{res}\sim 35--60 \mu\Omega$ and $\lambda_L(15 K)\sim 130--260 nm$]. The surface resistance $R_s$ is found to increase, decrease, or remain independent of the microwave field $H_{rf}$ (up to 60 mT) at different temperatures and for different samples. However, the surface reactance $X_s$ always follows the same functional form. Mechanisms which may be responsible for the observed variations in $R_s$ and $X_s$ are briefly discussed.Comment: 4 pages, 4 figure

Penetration Depth Measurements in MgB_2: Evidence for Unconventional Superconductivity

We have measured the magnetic penetration depth of the recently discovered binary superconductor MgB_2 using muon spin rotation and low field $ac$-susceptibility. From the damping of the muon precession signal we find the penetration depth at zero temperature is about 85nm. The low temperature penetration depth shows a quadratic temperature dependence, indicating the presence of nodes in the superconducting energy gap.Comment: 4 pages 3 figure

c-Axis Superfluid Response and Pseudogap in High-Tc Superconductors

To gain insight into the out-of-plane electrodynamics of high-$T_c$ superconduct ors we have measured the absolute values and temperature dependence of the c-a xis magnetic penetration depth $\lambda_c(T)$ for two typical single layer high -$T_c$ cuprates, La$_{2-x}$Sr$_x$CuO$_4$ and HgBa$_2$CuO$_{4+x}$ as a function o f doping. A distinct change in the behaviour of $\lambda_c$ is observed near 0. 20 holes/Cu, which is related to the opening of the normal state pseudogap. The variation of $\lambda_c$ with doping is qualitatively similar to that of the in -plane component, $\lambda _{ab}$, which suggests that the c-axis superfluid r esponse is mainly governed by the superconducting condensation energy. The stron g doping dependence of $\lambda_c(0)$ for p<0.20 provides an explanation for the discrepancies in the literature.Comment: 4 pages, 2 figure

Systematic behaviour of the in-plane penetration depth in d-wave cuprates

We report the temperature T and oxygen concentration dependences of the penetration depth of grain-aligned YBa_2Cu_3O_{7-\delta} with \delta= 0.0, 0.3 and 0.43. The values of the in-plane \lambda_{ab}(0) and out-of-plane \lambda_{c}(0) penetration depths, the low temperature linear term in \lambda_{ab}(T), and the ratio \lambda_{c}(0) /\lambda_{ab}(T) were found to increase with increasing $\delta$. The systematic changes of the linear term in \lambda_{ab}(T) with T_c found here and in recent work on HgBa_2Ca_{n-1} Cu_nO_{2n+2+\delta} (n = 1 and 3) are discussed.Comment: 4 pages, 4 figure

Pressure effect on the in-plane magnetic penetration depth in YBa_2Cu_4O_8

We report a study of the pressure effect (PE) on the in-plane magnetic field penetration depth lambda_{ab} in YBa_2Cu_4O_8 by means of Meissner fraction measurements. A pronounced PE on lambda_{ab}^{-2}(0) was observed with a maximum relative shift of \Delta\lambda^{-2}_{ab}/\lambda^{-2}_{ab}= 44(3)% at a pressure of 10.2 kbar. It arises from the pressure dependence of the effective in-plane charge carrier mass and pressure induced charge carrier transfer from the CuO chains to the superconducting CuO_2 planes. The present results imply that the charge carriers in YBa_2Cu_4O_8 are coupled to the lattice.Comment: 4pages 3 figure

Sex-Specific Growth and Reproductive Dynamics of Red Drum in the Northern Gulf of Mexico

The Red Drum Sciaenops ocellatus stock is heavily targeted in the Gulf of Mexico (GOM) by recreational fishers and supports a small commercial fishery in Mississippi. Despite their popularity, little recent work has been done to describe their life history. In this work, we describe sex‐specific growth and reproductive dynamics of Red Drum collected from the northern GOM from September 2016 through October 2017. We evaluated seven candidate growth models and found that the three‐parameter von Bertalanffy growth function (VBGF) was the best candidate length‐at‐age model. No significant difference in growth between sexes was observed with the three‐parameter VBGF, despite the female‐specific curve having a larger mean asymptotic length than the male‐specific curve. All seven candidate growth models predicted similar mean length‐at‐age estimates, and four of them exhibited significant differences in sex‐specific mean length at age, with females reaching a larger length at age than males after age 5. There was no significant difference between the sex‐specific weight‐at‐length relationships. Red Drum are batch spawners that spawn in northern GOM coastal waters during August and September. We estimated 3.7 d between spawns and 10.5 spawning events per female in 2017. Nearly 20% of fish collected during the spawning season were sexually mature but reproductively inactive, indicating the possibility of skipped spawning. The age at 50% maturity was around 3 years (length at 50% maturity = 670 mm TL) in both sexes, but fish were not spawning capable until age 4.5 (703 mm TL) in males and age 5.8 (840 mm TL) in females. Furthermore, elevated gonadosomatic indices were not observed until around age 5–6. The updated life history information presented in this work helps to address current data limitations and provides critical information for future assessments of Red Drum stocks in the northern GOM

Temperature stress differentially modulates transcription in meiotic anthers of heat-tolerant and heat-sensitive tomato plants

Contains fulltext : 92405.pdf (publisher's version ) (Open Access

The Real maccoyii: Identifying Tuna Sushi with DNA Barcodes – Contrasting Characteristic Attributes and Genetic Distances

BACKGROUND:The use of DNA barcodes for the identification of described species is one of the least controversial and most promising applications of barcoding. There is no consensus, however, as to what constitutes an appropriate identification standard and most barcoding efforts simply attempt to pair a query sequence with reference sequences and deem identification successful if it falls within the bounds of some pre-established cutoffs using genetic distance. Since the Renaissance, however, most biological classification schemes have relied on the use of diagnostic characters to identify and place species. METHODOLOGY/PRINCIPAL FINDINGS:Here we developed a cytochrome c oxidase subunit I character-based key for the identification of all tuna species of the genus Thunnus, and compared its performance with distance-based measures for identification of 68 samples of tuna sushi purchased from 31 restaurants in Manhattan (New York City) and Denver, Colorado. Both the character-based key and GenBank BLAST successfully identified 100% of the tuna samples, while the Barcode of Life Database (BOLD) as well as genetic distance thresholds, and neighbor-joining phylogenetic tree building performed poorly in terms of species identification. A piece of tuna sushi has the potential to be an endangered species, a fraud, or a health hazard. All three of these cases were uncovered in this study. Nineteen restaurant establishments were unable to clarify or misrepresented what species they sold. Five out of nine samples sold as a variant of "white tuna" were not albacore (T. alalunga), but escolar (Lepidocybium flavorunneum), a gempylid species banned for sale in Italy and Japan due to health concerns. Nineteen samples were northern bluefin tuna (T. thynnus) or the critically endangered southern bluefin tuna (T. maccoyii), though nine restaurants that sold these species did not state these species on their menus. CONCLUSIONS/SIGNIFICANCE:The Convention on International Trade Endangered Species (CITES) requires that listed species must be identifiable in trade. This research fulfills this requirement for tuna, and supports the nomination of northern bluefin tuna for CITES listing in 2010