The heritability of resistance to early blight in diploid potatoes (Solanum tuberosum, subsp.Phureja andStenotomum)
The heritability of resistance to early blight caused byAlternaria solani (Ell. & Martin) Son was estimated for field grown, diploid potatoes at Fletcher, North Carolina in 1981. Fourteen breeding lines, selected from a random mated hybrid population ofSolanum tuberosum, subsp.phureja andstenotomum, were used. Resistance was measured as the slope obtained by regressing the logit of the disease proportion Y, measured as % defoliation, on time. A wide range of resistance was found. Narrow-sense heritability, as determined by offspring-midparent regression, on an individual plant basis, was calculated to be 0.825.
Population breeding as a tool for germplasm enhancement
The genetic basisof Solanum tuberosum ssp.tuberosum has been discussed focusing on the importance of increasing its genetic variability. A review of the work on germplasm enhancement, using both cultivated, primitive and wildSolanum species, carried out by several institutions, has been made. Through these research efforts, mainly based on a population breeding strategy, new sources of genetic variability for yield, tuber quality factors, and pest, disease, and stress resistance or tolerance have been identified. The utilization of these new breeding resources has already started to produce results. In the last few years at least 30 new varieties, carrying resistance to one or more pests, diseases, or stresses, have been released in several countries.CompendioSe ha discutido la base genética deSolanum tuberosum ssp.tuberosum enfocando la importancia de incrementar su variabilidad genética. Asimismo, se ha hecho una revisión del trabajo de mejoramiento de germoplasma llevado a cabo por varias instituciones, utilizando especies cultivadas primitivas y silvestres del géneroSolanum. Estos trabajos de investigación, principalmente basados en una estrategia de mejoramiento poblacional, han permitido identificar neuvas fuentes de variabilidad genética para rendimiento, factures de calidad del tubérculo, y resistencia o tolerancia a enfermedades, plagas, y factores climáticos adversos. La utilización de estos nuevos recursos genéticos para el mejoramiento-ha comenzado a producir resultados. En los últimos años se han liberado por lo menos 30 nuevas variedades en varios paises. Estas nuevas variedades se caracterizan por su resistencia a una o mas enfermedades, plagas, o factores climáticos adversos.
A Study on Greenhouse Automatic Control System Based on Wireless Sensor Network
The system proposed in this paper collects temperature of leaves and humidity on leaves of crop. As well as greenhouse environmental information such as temperature, humidity, etc. Crop diseases, especially, have deep relationship not only with indoor environmental factors but also with humidity lasting time on leaves and temperature of leaves. Accordingly, monitoring crop itself is as important as monitoring indoor environments. Using these collected greenhouse environmental data, indoor environments can be more effectively controlled, and monitoring crop itself can contribute to improve productivity and to prevent crops from damages by blight and harmful insects. In addition, it will be possible for farmers to do control plant growth through closely studying relationship between indoor environmental information and monitored information on crop itself. Collected data can be stored to database either in server installed in greenhouse or to remote server. It is made possible to collect information and control effectively and automatically greenhouse in the site or from a remote place through web browser. System components are: temperature sensor, humidity sensor, leaf temperature sensor, leaf humidity sensor, Zigbee based wireless sensor node, relay nodes for automatic control, and data server to store greenhouse information. The system is implemented using low power wireless components, and easy to install.