The choice of locality for plant breeding when selecting for high yield and general adaptation

Summary The choice of localities for initial yield testing of selections in a plant breeding programme is often arbitary. We describe a method that allows a more objective approach based on the correlation between the performance of varieties in a locality and their performance over a large area. The method was checked using data from the Western Australian Department of Agriculture regional wheat variety testing programme, and it was found possible to identify combinations of localities which produced significant predictions over both years and genotypes.     

Multiple allelism at a major locus affecting fruit coloration in Cucurbita pepo

The l-2 (light coloration-2) locus in Cucurbita pepo (pumpkin, squash, gourd) has a major effect on fruit color intensity through its complementary interactions with at least three other loci. From a sixth-generation backcross progeny of which a wild gourd having striped fruits was the donor parent and a cultigen having ‘plain light’-colored fruits(genotype l-2/l-2) was the recurrent parent, a true-breeding line was isolated that had a fruit color phenotype that differed from both parents. The fruits of this line were not striped and had a color pattern resembling‘light type 2’ (genotype L-2/–-), but of weaker expression. This newly established line was then crossed with near-isogenic lines of genotypes l-2/l-2 and L-2/L-2 and the resulting filial and backcross progenies were observed under field conditions. The results indicated that the new phenotype is recessive to ‘light type 2’ but dominant to ‘plain light’ and that it is conferred by a single gene. The results of a testcross for allelism indicated that this gene is an allele at the l-2 locus and it is herein designated L-2 ^w. Dominance relationships at the l-2 locus are L-2 > L-2 ^w >l-2. This revised version was published online in July 2006 with corrections to the Cover Date.     

Efficacy of food proteins as carriers for flavonoids

Enrichment of flavonoids in food is often limited by their off-tastes, which might be counteracted by the use of food proteins as carriers of flavonoids. Various milk proteins, egg proteins, and gelatin hydrolysates were compared for their binding characteristics to two flavan-3-ols. Among the proteins tested for their affinities toward epigallocatechin gallate (EGCG), β-casein and gelatin hydrolysates, in particular fish gelatin, were found to be the most promising carriers with an affinity on the order of 10(4) M(-1). A flexible open structure of proteins, as present in random coil proteins, was found to be important. The saturation of binding observed at high flavonoid/protein ratios was used to estimate the maximal binding capacity of each protein. To reach a daily intake of EGCG that has been associated with positive health effects, only 519 mg of gelatin B and 787 mg of β-casein were required to complex EGCG on the basis of their maximal binding capacity. When the absence of turbidity is taken into account, β-casein prevails as carrier. Three selected proteins were further investigated for their binding potential of representative flavonoids differing in their C-ring structure. An increase in hydrophobicity of flavonoids was related to a higher affinity for proteins, and the presence of a gallic acid ester on the C-ring showed an overall higher affinity.     

Oxoiron(IV) in chloroperoxidase compound II is basic: implications for P450 chemistry

With the use of x-ray absorption spectroscopy, we have found that the Fe-O bond in chloroperoxidase compound II (CPO-II) is much longer than expected for an oxoiron(IV) (ferryl) unit; notably, the experimentally determined bond length of 1.82(1) A accords closely with density functional calculations on a protonated ferryl (Fe(IV)-OH, 1.81 A). The basicity of the CPO-II ferryl [pKa > 8.2 (where Ka is the acid dissociation constant)] is attributable to strong electron donation by the axial thiolate. We suggest that the CPO-II protonated ferryl is a good model for the rebound intermediate in the P450 oxygenation cycle;with elevated pKa values after one-electron reduction, thiolate-ligated ferryl radicals are competent to oxygenate saturated hydrocarbons at potentials that can be tolerated by folded polypeptide hosts.     

Local government and rural development in the bengal Sundarbans: An inquiry in managing common property resources

Of the three strategies available for managing common property resources (CPR)—centralized control, privatization and local management—this essay focuses on the last, which has proven quite effective in various settings throughout the Third World, with the key to success being local ability to control access to the resource. The major factors at issue in the Sundarbans situation are: historically external pressure on the forest; currently dense population in adjacent areas; a land distribution even more unequal than the norm in Bangladesh; and a decentralized local government structure initiated in the mid-1980s. The first three factors have encouraged the local population to view this CRP as a frontier to be exploited,rather than as a resource to be preservedfor sustained yield. Thus to the extent that the new local government structure proves to be democratic and responsive to popular needs, it would most likely accelerate destruction of the Sundarbans, using the area as a cheap and easy way to provide some livelihood to the rural poor and landless. Accordingly, decentralization cannot be a viable strategy for preserving this unique forest resource; only a strong central control can ensure its survival into the next century. 1. The original version of this paper was prepared for the Sundarbans Workshop, sponsored by the Smithsonian Institution and the Joint Committee on South Asia of the Social Science Research Council and the American Council of Learned Societies, Washington, DC, 20–21 November 1987.     

Exercise and genetic rescue of SCA1 via the transcriptional repressor Capicua

Spinocerebellar ataxia type 1 (SCA1) is a fatal neurodegenerative disease caused by expansion of a translated CAG repeat in Ataxin-1 (ATXN1). To determine the long-term effects of exercise, we implemented a mild exercise regimen in a mouse model of SCA1 and found a considerable improvement in survival accompanied by up-regulation of epidermal growth factor and consequential down-regulation of Capicua, which is an ATXN1 interactor. Offspring of Capicua mutant mice bred to SCA1 mice showed significant improvement of all disease phenotypes. Although polyglutamine-expanded Atxn1 caused some loss of Capicua function, further reduction of Capicua levels--either genetically or by exercise--mitigated the disease phenotypes by dampening the toxic gain of function. Thus, exercise might have long-term beneficial effects in other ataxias and neurodegenerative diseases.     

Deeply inverted electron-hole recombination in a luminescent antibody-stilbene complex

The blue-emissive antibody EP2-19G2 that has been elicited against trans-stilbene has unprecedented ability to produce bright luminescence and has been used as a biosensor in various applications. We show that the prolonged luminescence is not stilbene fluorescence. Instead, the emissive species is a charge-transfer excited complex of an anionic stilbene and a cationic, parallel pi-stacked tryptophan. Upon charge recombination, this complex generates exceptionally bright blue light. Complex formation is enabled by a deeply penetrating ligand-binding pocket, which in turn results from a noncanonical interface between the two variable domains of the antibody.     

Altered pesticide use on transgenic crops and the associated general impact from an environmental perspective

The large-scale commercial cultivation of transgenic crops has undergone a steady increase since their introduction 10 years ago. Most of these crops bear introduced traits that are of agronomic importance, such as herbicide or insect resistance. These traits are likely to impact upon the use of pesticides on these crops, as well as the pesticide market as a whole. Organizations like USDA-ERS and NCFAP monitor the changes in crop pest management associated with the adoption of transgenic crops. As part of an IUPAC project on this topic, recent data are reviewed regarding the alterations in pesticide use that have been observed in practice. Most results indicate a decrease in the amounts of active ingredients applied to transgenic crops compared with conventional crops. In addition, a generic environmental indicator -- the environmental impact quotient (EIQ) -- has been applied by these authors and others to estimate the environmental consequences of the altered pesticide use on transgenic crops. The results show that the predicted environmental impact decreases in transgenic crops. With the advent of new types of agronomic trait and crops that have been genetically modified, it is useful to take also their potential environmental impacts into account.