Information:  - A grape is a fruit, botanically a berry, of the deciduous woody vines of the flowering plant genus "Vitis".  - Pseudoperonospora is a genus of water moulds which includes several species known for causing downy mildew infections on plants . Species include : Pseudoperonospora cannabina - causes downy mildew on hemp Pseudoperonospora cubensis - causes downy mildew on cucurbits Pseudoperonospora humuli - causes downy mildew on hops  - In everyday usage, a vegetable is any part of a plant that is consumed by humans as food as part of a savory meal. The term "vegetable" is somewhat arbitrary, and largely defined through culinary and cultural tradition. It normally excludes other food derived from plants such as fruits, nuts, and cereal grains, but includes seeds such as pulses. The original meaning of the word "vegetable", still used in biology, was to describe all types of plant, as in the terms "vegetable kingdom" and "vegetable matter".  - Downy mildew refers to any of several types of oomycete microbes that are obligate parasites of plants. Downy mildews exclusively belong to Peronosporaceae. In commercial agriculture, they are a particular problem for growers of crucifers, grapes and vegetables that grow on vines. The prime example is "Peronospora farinosa" featured in NCBI-Taxonomy and HYP3. This pathogen does not produce survival structures in the northern states of the United States, and overwinters as live mildew colonies in Gulf Coast states. It progresses northward with cucurbit production each spring. Yield loss associated with downy mildew is most likely related to soft rots that occur after plant canopies collapse and sunburn occurs on fruit. Cucurbit downy mildew only affects leaves of cucurbit plants.  - Peronosporaceae are a family of water moulds that contains 17 genera, comprising more than 600 species. Most of them are called downy mildews. The closest relative of Peronosporaceae is "Phytophthora".  - Oomycota or oomycetes form a distinct phylogenetic lineage of fungus-like eukaryotic microorganisms. They are filamentous, microscopic, absorptive organisms that reproduce both sexually and asexually. Oomycetes occupy both saprophytic and pathogenic lifestyles, and include some of the most notorious pathogens of plants, causing devastating diseases such as late blight of potato and sudden oak death. One oomycete, the mycoparasite "Pythium oligandrum", is used for biocontrol, attacking plant pathogenic fungi. The oomycetes are also often referred to as water molds (or water moulds), although the water-preferring nature which led to that name is not true of most species, which are terrestrial pathogens. The Oomycota have a very sparse fossil record. A possible oomycete has been described from Cretaceous amber.  - Agriculture is the cultivation and breeding of animals, plants and fungi for food, fiber, biofuel, medicinal plants and other products used to sustain and enhance human life. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the development of civilization. The study of agriculture is known as agricultural science. The history of agriculture dates back thousands of years, and its development has been driven and defined by greatly different climates, cultures, and technologies. Industrial agriculture based on large-scale monoculture farming has become the dominant agricultural methodology.  - Peronospora farinosa is a plant pathogen. It causes downy mildew on leaves of wild and cultivated "Amaranthaceae": "Amaranthus", "Atriplex", "Bassia", "Beta", "Chenopodium", "Halimione", "Salsola", "Spinacia", etc. In the past, the forms of "Peronospora" on these different genera, and their species, were given different species names, but these downy mildews are now generally considered to be forms of one species "P. farinosa" (see "Index Fungorum"). Some of the forms on important crop plants have been given names as "formae speciales", notably "f.sp. betae" on sugar beet (= "P. schachtii") and f.sp. "spinaciae" on spinach. Such host specialization possibly also exists with respect to the various wild amaranthaceous hosts of "P. farinosa".    Given the information, choose the subject and object entities that have the relation of 'parent taxon'.
A:
pseudoperonospora , peronosporaceae