Heat stress effects on crop performance and tools for tolerance breeding

Abiotic stress is one of the most common causes of crop deficit and loss and hence an important area of study. Moreover, concerns regarding global climate change over past decades mean the study of different abiotic stresses appears to be essential if its effects are to be mitigated. The current review covers the effects of heat stress on crop performance, the response crops make when subjected to this stress and the development of tools designed to breed for stress tolerant crops. Distinct levels of the problem are considered, from the morphological/anatomical, through the physiological and to the biochemical/molecular. The study of heat shock proteins (HSPs), quantitative trait loci (QTLs) identification and the relationship between metabolomics (OMICS) and heat stress are given special consideration.Considerando el estrés abiótico como una de las causas más comunes de déficit y las pérdidas de las cosechas resulta muy importante investigar a fondo esta temática. Por otra parte, teniendo en cuenta que los cambios climáticos globales son uno de los problemas que se enfrentan en las últimas décadas, el estudio de los diferentes tipos de estrés abiótico es esencial. La presente revisión se refiere a los efectos del estrés por calor sobre la performance de los cultivos, la respuesta generada por ellos sujetos a este estrés y el desarrollo de herramientas diseñadas para el mejoramiento genético de cultivos tolerantes al mismo. Se consideran distintos niveles de la problemática, desde lo morfológico/anatómico, a través de lo fisiológico y a lo bioquímico/molecular. Se presta especial consideración al estudio de las proteínas de choque térmico (HSPs), a la identificación de los loci de caracteres cuantitativos (QTLs) y a la relación entre la metabolómica (OMICS) y el estrés térmico

A representation of the natural numbers by means of cycle-numbers, with consequences in number theory

In this paper we give rules for creating a number triangle T in a manner analogous to that for producing Pascal’s arithmetic triangle; but all of its elements belong to {0, 1}, and cycling of its rows is involved in the creation. The method of construction of any one row of T from its preceding rows will be defined, and that, together with starting and boundary conditions, will suffice to define the whole triangle, by sequential continuation. We shall use this triangle in order to define the so-called cycle-numbers, which can be mapped to the natural numbers. T will be called the ‘cyclenumber triangle’. First we shall give some theorems about relationships between the cyclenumbers and the natural numbers, and discuss the cycling of patterns within the triangle’s rows and diagonals. We then begin a study of figures (i.e. (0,1)patterns, found on lines, triangles and squares, etc.) within T. In particular, we shall seek relationships which tell us something about the prime numbers. For our later studies, we turn the triangle onto its side and work with a doubly-infinite matrix C. We shall find that a great deal of cycling of figures occurs within T and C, and we exploit this fact whenever we can. The phenomenon of cycling patterns leads us to muse upon a ‘music of the integers’, indeed a ‘symphony of the integers’, being played out on the cycle-number triangle or on C. Like Pythagoras and his ‘music of the spheres’, we may well be the only persons capable of hearing it! Keywords: cycle-number triangle, cycle-number, prime cycle-number

Order to pay Chu walookee $7.50 from public funds for his services, endorsed by John Ross on verso. August 23, 1834.

Order to pay and authorization by John Ross for $7.50 of public funds be paid to Chuwalookee for his services. Dated August 23rd, 1834.https://digitalcommons.wofford.edu/littlejohnmss/1249/thumbnail.jp

Canaryseed (Phalaris canariensis L.) accessions from nineteen countries show useful genetic variation for agronomic traits

Fifty-seven accessions of canaryseed (47 populations and 10 cultivars) from 19 countries were evaluated for agronomic traits in four field trials sown over 3 yr in the province of Buenos Aires, Argentina. Genetic variation was found for all traits scored: grain yield and its components (grain weight, grain number per square meter, grain number per head and head number per square meter), harvest index, percent lodging, and phenological characters (emergence to heading, emergence to harvest maturity and heading to harvest maturity). Although genotype×environment interaction was observed for all traits, the additive differences between accessions were sufficient to enable promising breeding materials to be identified. Accessions superior in performance to the local Argentinean population, which in general gave values close to the overall mean of the accessions evaluated, were identified. For example, a population of Moroccan origin gave good yield associated with elevated values of the highly heritable character grain weight, rather than with the more commonly observed grain number per square meter. This population was also of relatively short stature and resistant to lodging, and, although it performed best when sown within the normal sowing date, tolerated late sowing fairly well. Other accessions were also observed with high grain weight, a useful characteristic in itself, since large grains are desirable from a quality point of view. Regarding phenology, the accessions showed a range of 160 degree days (8 calendar days in our conditions) in maturity, which, while not large in magnitude, may be of some utility in crop rotation management. Some accessions were well adapted to late sowing. Grain yield in general was strongly correlated with grain number per square meter. Principal components analysis (PCA) carried out for all characteristics provided indications of accessions combining useful characteristics and identified three components that explained approximately 70% of the phenotypic variation. Furthermore, a second PCA plus regression showed that approximately 60% of the variation in grain yield could be explained by a component associated with harvest index and grain number per square meter. Pointers were provided to possible future breeding targets

Tribes\u27 Reply to the State

The Tribes\u27 response to basic arguments made by the State, with reference to its proposed findings and the Tribes\u27 proposed findings, where appropriate

Tribes\u27 Reply to the State

The Tribes\u27 response to basic arguments made by the State, with reference to its proposed findings and the Tribes\u27 proposed findings, where appropriate