Breeding crop plants

Abstract

Classification and inheritance in barley Species crosses 99 Simple Mendelian characters Winter versus spring habit 103 Density of the spike 103 The barley awn in relation to yield Some rye studies Wheat-rye hybrids Buckwheat Breeding buckwheat Rice Inheritance of characters CHAPTER VIII METHODS OF BREEDING SMALL GRAINS Method of keeping continuous records Ill New introductions 113 Select'on 114 Summary of methods of selection 115 Crossing 116 Technic of harvesting, thrashing, etc CHAPTER IX SOME RESULTS OF SELECTION WITH SELF-FERTILIZED CROPS Early investigators in selection of self-fertilized cereals Selection within a pure line Selection for the purpose of isolating a pure line 125 2 BREEDING CROP PLANTS times by primitive peoples who developed many varieties. As some of the varieties which were then grown are in existence today and are cultivated in some regions, a little idea of earlier work is obtained. Coming now more nearly to present times we may briefly consider the work of the Indians with maize. Piper speaks of the plan by which seeds of different colors were planted together in one hill with the thought that this method gave increased yields. It tended to keep the varieties in a heterozygous condition. During the last three or four years Squaw Flint from the Indian reservations in Minnesota has averaged as large a yield per acre at University Farm, St. Paul, as the more carefully selected varieties. These facts should help to give the student of plant-breeding some idea of the great accomplishments in plant production in earlier times and to correct possible exaggeration of relative values of the results of recent work. Present-day breeding has achieved great results and will accomplish much more; the foundation, however, was laid many years ago. THE FOUNDERS OF THE ART OF PLANT BREEDING The relation between the science and the art of plant breeding is a very interesting subject. Through many years of trials, methods are improved; and a correct knowledge of the fundamentals of the science often does not widely modify the actual practice involved. As a rule, scientific principles allow some short cuts in breeding methods and help to eliminate erroneous and useless practices. As will be constantly emphasized in this work, there is a close relation between the mode of reproduction and the methods of breeding a plant. A knowledge of sexuality was, therefore, almost a necessity before it was possible to develop the art of breeding. Sexual processes, while not thoroughly understood, were observed in animals three or four centuries B.C. by the Egyptians and Assyrians. Existence of fruit-bearing and sterile trees of the date palm was known to the people of Egypt and Mesopotamia in early times and records of artificial pollination as early as 700 years B.C. have been found (see Fig. 1). The Assyrians commonly referred to the date trees as male and female. The Greeks, however, to whom we look for early FIG. 2. Male and female flowers of date palm about two times natural size. (Photograph taken by Swingle in Sah...

Outcrossing Rates in Barley Populations in the Canadian Prairies

“…Smooth-awned barley, in contrast, does not have such teeth. Awn texture is controlled by a major gene, R/r (Hayes and Garber, 1921;Wexelsen, 1934). The R allele is completely dominant to r. With regard to awn texture, both Awnless and Full-awned Atlas are rough-awned, whereas the other parents, Bonanza, Galt and Minnesota 5 are smooth-awned.…”

Adaptedness and Heterosis in Corn and Mule Hybrids

“…Hayes and Immer (1942) defined combining ability as the relative ability of a biotype to transmit desirable performance to its crosses. Inbreds must yield enough to make seed corn production profitable (Hayes and Garber, 1921). Richey (1924) and Richey and Mayer (1925) found that certain inbreds gave higher yielding crosses.…”

Natural Crossings in Oats at Akron, Colorado1

“…Hayes and Garber (7) state that Pridham observed a natural cross between Avena sterilis and A. nuda in rgr6. These authors consider that numerous statements by breeders as to self-fertilization show that natural crossing occurs much less frequently in oats than in wheat.…”

“…These statements from different investigators indicate that their opinions vary as to the amount of natural crossing which may occur in oats. Jamieson (u) who believed that natural crossing in oats occurs very commonly, is contrasted with McAlpine (15), Norton (14), Hays (8), Hunt (9), Pope (17), Love and Craig (13), Fraser (6), and Hayes and Garber (7), who believe that natural crossing seldom occurs.…”