Plant-breeding: Being Six Lectures Upon the Amelioration of Domestic PlantsMacmillan, 1906 - 483 páginas |
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Términos y frases comunes
adapted Agric Agriculture anther appear apples atavism beans breeder breeding buds Bull calyx Canna cent characters Chron Citrange color common wheats corn cotton crops Cross-Fertilization cultivation desired Deut dominant dwarf ears Editorial emasculated evolution experiment stations fact female parent fertile flowers Forest fruits gametes garden grapes growing grown hardy heads heredity Hort horticultural ideal illustrated Improvement inches individual Internat Journ Keeney kernels kind Landw Luther Burbank male parent Mendel Mendel's law Mendelian mutations N. Y. Mem natural selection nature nearly offspring Orchids organs original P. B. Form pangene peas pistillate plant-breeding Plant-Breeding and Hybridization plums pollen pomelo potato Proc produce progeny propagated protein races riety secure seedlings seeds selection sepals sheet sown species squash stamens stigma strawberries tangelo tion tomato trees true types U. S. Dept Ueber variable variation varieties vary Vries Webber wheat xxvi
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Página 32 - And the earth brought forth grass, and herb yielding seed after his kind, and the tree yielding fruit, whose seed was in itself, after his kind: and God saw that it was good.
Página 89 - We cannot suppose that all the breeds were suddenly produced as perfect and as useful as we now see them ; indeed, in many cases, we know that this has not been their history. The key is man's power of accumulative selection : nature gives successive variations; man adds them up in certain directions useful to him.
Página 72 - ... with pollen from another individual or variety of the same species, they are fully fertile ; but if with pollen from a distinct species, they are sterile in all possible degrees, until utter sterility is reached. We thus have a long series with absolute sterility at the two ends ; at one end due to the sexual elements not having been sufficiently differentiated, and at the other end to their having been differentiated in too great a degree, or in some peculiar manner.
Página 25 - I saw how), from the simple circumstance that the more diversified the descendants from any one species become in structure, constitution, and habits, by so much will they be better enabled to seize on many and widely diversified places in the polity of nature, and so be enabled to increase in numbers.
Página 19 - Alexander Braun,4 an earlier writer on natural history, says that " it appears, rather, on the whole as if the unusual conditions favorable to a luxuriant state of development, afforded by cultivation^ awakened in the plant the inward impulse to the display of all those variations possible within the more or less narrowly circumscribed limits of the species." These statements illustrate the feeling of the earlier writers in regard to this question. It is only within the last few years that we have...
Página 118 - A decrease in nutrition during the period of growth of an organism favors the development of the reproductive parts at the expense of the vegetative parts." Although the case presented is not exactly parallel to that of plants subjected to unbroken poverty of nutrition from the beginning of their lives, the same discrimination seems to take place when an entire species is compelled to struggle against adverse conditions.
Página 63 - ... interfere with the carrying on of actions and reactions like those just described. Here, as before, we have a definitely-arranged aggregate of parts, which we call organs, having their definitely-established actions and reactions, which we call functions. These rhythmical actions or functions, and the various compound rhythms resulting from their combinations, are in such adjustment as to balance the actions to which the organism is subject : there is a constant or periodic genesis of forces,...
Página 214 - The horny layer, which usually constitutes about sixty-five per cent, of the corn kernel, contains a large proportion of the total protein in the kernel. " The white, starchy part constitutes about twenty per cent, of the whole kernel, and contains a small proportion of the total protein. The germ constitutes only about ten per cent, of the corn kernel, but while it is rich in protein, it also contains more than eighty-five per cent, of the total oil content of the whole kernel, the remainder of...
Página 142 - ... ground but which had re-rooted. It bore three pods, each containing one seed. These three seeds were planted in 1884, and two of the plants were dwarf, like the parent. By discarding all plants which had a tendency to climb, in succeeding crops, the Burpee Bush Lima, as we now have it, was developed. The singular Barteldes Bush Lima came from Colorado and is a similar dwarf sport of the old White Spanish or Dutch Runner bean. Barteldes received about a peck of the seed and introduced it sparingly....