Search results for "botany"

The development of sporangia of Phytophthora infestans

1995

The dynamics of sporulation and zoosporogenesis of Phytophthora infestans in a naturally infected crop of potato cv. Maris Bard and on potted plants of the same cultivar infected artificially with the same fungus are described. Development of sporangiophores and sporangia was synchronous after induction. Migration of several nuclei from the sporangiophore into the sporangium initial was followed by nuclear division, then by degeneration of a proportion of the nuclei. Sporangia then became deciduous, developed papillae and became able to release zoospores in rapid succession. When infected leaves were detached and transferred from the field to moist Petri dishes, sporulation was at first syn…

Duplication cycle in nuclei of germinating zoospores of Phytophthora drechsleri as revealed by DAPI staining

1982

Volatile and contact chemicals released by Nezara viridula (Heteroptera: Pentatomidae) have a kairomonal effect on the egg parasitoid Trissolcus basa…

1999

The responses of females of the egg parasitoid Trissolcus basalis (Wollaston) (Hymenoptera: Scelionidae) to volatile and contact chemicals from its host Nezara viridula (L.) (Heteroptera: Pentatomidae) were investigated in a Y-tube olfactometer and under open arena conditions. In the Y-tube tests, volatiles from virgin males and from females in a preovipositional state attracted T. basalis females, while volatiles from host virgin females did not. In an open arena, traces left by N. viridula adults in different physiological conditions function as contact cues inducing the wasps to remain longer in the arena and to change the pattern of their walking behavior. However, only contact kairomon…

Effect of polyamines on in vitro anther culture of Citrus clementina Hort. ex Tan

2006

The improvement of the induction rate in Citrus anther culture is important for taking practical advantage of the haploid potential in breeding. The influence of polyamines on anther culture of Citrus clementina, cv Nules, with particular attention to the free, soluble and insoluble-conjugated polyamine levels, has been investigated. Putrescine, spermidine and putrescine plus spermidine, were added to the standard induction medium. Before culture, spermidine was the most abundant among the free polyamines detected in anthers. The exogenous supply of either putrescine or spermidine, either independently or combined, effected greater uptake and accumulation of polyamines. The addition of 2 mM…

Essential oil composition and antifeedant properties of Bellardia trixago (L.) All. (sin. Bartsia trixago L.) (Scrophulariaceae)

2008

New records of Cynipidae (Hymenoptera) from Italy

2015

New records of Cynipid gall wasps and inquilines for the Italian peninsula and Sicily and their new host plants for the Palaearctic Region are listed and commented on. Among them we find: Cerroneuroterus cerrifloralis (Mullner 1901) as new for Italy and new for the Palaearctic region as host on Quercus suber; Andricus multiplicatus Giraud 1859 on Q. suber, as new host for the Palaearctic region; Aylax papaveris (Perris 1839), reported in Italy over a century ago, but later overlooked; Cerroneuroterus minutulus (Giraud 1859), also reported more than a century ago from Sicily, but later overlooked. Among the inquilines are here listed: Synergus variabilis Mayr 1872, emerged from Janetia cerri…

La lucha por el mantenimiento de un huerto de simples en la universidad de Valencia durante el siglo XVII

2005

This article deepens on the efforts made during the 17th century by Medicine professors and students, Pharmacist Associations as well as surgeons and magistrates from Valencia directed toward the creation and mantenaince of a garden destinated to the growing of medicinal plants from worldwide.

Ecological distribution and characterization of four collections ofBacillus thuringiensisstrains

2008

Four Collections comprising 507 strains of Bacillus thuringiensis have been analysed in this study. A different ecological origin characterizes each collection. Collection No. 1 was established from soil, dust, and grain samples from Spanish agricultural and non-cultivated soil, silos, and mills. Collection No. 2 is the result of a screening in olive-crop related environments in Spain. Collection No. 3 is made up of strains isolated from potato-growing areas in Bolivia. Collection No. 4 has been generated for this study and includes strains collected from diverse types of samples belonging to several habitats from Spain and Mexico. Crystal morphologies and cry1A and cry2 gene content were a…

Viral diseases causing the greatest economic losses to the tomato crop. II. The Tomato yellow leaf curl virus — a review

1996

Abstract Tomato yellow leaf curl geminivirus (TYLCV), transmitted by the whitefly Bemisia tabaci (Gennadius) is one of the most devastating diseases of cultivated tomato (Lycopersicon esculentum Mill.). TYLCV causes economic losses up to 100% in tomato crop in many tropical and subtropical regions, and is spreading towards new areas. The increasing economic importance of TYLCV has resulted in the need for accurate detection and identification procedures, stimulating intensive research efforts focused on virus biology, diversity, and epidemiology to develop successful control strategies. Breeding for resistance appears to be the best approach to control this disease, but to date only partial…

Tipificación de dos nombres del género Verbascum incluidos en la subsect. Singuliflora (Scrophulariaceae)

2020

Se designan los tipos nomenclaturales de Verbascum barnadesii y V. fontqueri (≡ Celsia valentina (Scrophulariaceae) a partir de especímenes conservados en los herbarios C y BC, respectivamente.