Plant Biology Commons^™

Pensternon In Your Garden, Glenn Viehmeyer

Department of Agronomy and Horticulture: Faculty Publications

A new race of hardy perennials is beginning to appear in American gardens. These are the penstemons, a genus of plants closely related to the familiar snapdragon, which may become important ornamentals as they become better known to gardeners. The purpose of this bulletin is to show the possibility of the genus as an ornamental and to suggest species and species hybrids of possible value to Great Plains gardeners; to provide information about propagation and culture; and to encourage gardeners to engage in penstemon breeding as an avocation.

Hormone Sprays For Apricots, J E L Cripps

Journal of the Department of Agriculture, Western Australia, Series 4

VARIOUS hormone sprays have been applied to apricots with the object of increasing fruit size and hastening maturity, and of these 245TA, the tri-ethanol amine salt of 245 trichlorophenoxyacetic acid, has in general, proved the most successful.

The increase in fruit diameter obtained with this spray in Western Australia has varied between 5 and 15 per cent, and is due to an increase in the size of the cells within the fruit, not to the production of a greater number of cells.

The Budding Of Fruit Trees, T F. Herlihy

Journal of the Department of Agriculture, Western Australia, Series 4

A LTHOUGH the principles of budding and grafting are basically the same—that is, t h e success depends upon the close contact of the cambium layers of both stock and scion—the operations are performed at different times of the year.

Influence Of Atmospheric And Soil Moisture Conditions On Diurnal Variations In Relative Turgidity Of Potato Leaves, H. O. Werner

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The experimental work reported herein was planned to determine: 1. The extent and nature of the changes of the relative turgidity (R.T.) of leaves of the potato plant during the diurnal cycle. 2. The extent to which R.T. of potato leaves is influenced by atmospheric conditions, soil moisture, variety and age of plants. 3. The extent to which visible evidence of water shortage in leaves is indicative of water loss from them as revealed by R.T. and the extent to which this relationship varies with different varieties. 4. The nature of the relationships between morphological characteristics of leaves and stems …

Microorganisms And Soil Structure, T. M. Mccalla

Department of Agronomy and Horticulture: Faculty Publications

SUMMARY

Laboratory tests were made to determine the effectiveness of different compounds and microbial groups in increasing the stability of Peorian loess lumps against the action of falling water drops. The influence of these on percolation tests in the laboratory was also determined.

Many organic substances-dextrose, sucrose, starch, peptone, cullulose, and gum arabic-did not themselves contribute directly to soil-structure stability, though these substances do furnish energy material for soil microorganisms, which can convert them readily into either microbial tissue or decomposition products that increase soil-structure stability. Lignin, proteins, oils, fats, waxes, resin, and paraffin increased the stability of lumps of …

Effect Of Storage Temperatures On Triumph Seed Potatoes Used For The Early Crop In The South And In Central Nebraska, H. O. Werner

Nebraska Agricultural Experiment Station: Historical Research Bulletins

During the decade 1931-1940 it became increasingly apparent that some factor (or factors) besides disease was responsible for much of the variation in yields produced by lots of certified seed potatoes planted in commercial fields and comparative trial plots in the South during midwinter. This bulletin reports investigations into the method of storing western Nebraska seed potatoes as a means of improving the production of the early crop of Triumphs in the Gulf Coast States.

A Study Of Origins And Ecological Features Of Hardy, Cultivated, Herbaceous Plants Of Milwaukee, Wisconsin, Dorothy Elaine Witheck

Bachelors’ Theses

Gardeners have always been interested in herbaceous plants, chiefly because of their beauty and usefulness. As a result of the great popularity, a large number of attractive varieties have been produced through centuries of' cultivation, selection and breeding. Very early agricultural and medical demands stimulated an interest in the plants, and as early as 372-287 B.C. Theophrastus, a pupil of Aristotle, described about 460 cultivated plants and classified them as herbs, undershrubs, shrubs and trees. Much of the work accomplished by the ancient Greeks was lost and it was not until the sixteenth century that renewed enthusiasm for the study …

The Genetics Congress, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

Mice and men reported from

Edinburgh after the Congress

(JOURNAL OF HEREDITY for

September 1939) but since then there

has been silence, as far as getting into the

record any details of the Congress. On

account of the disruption to trans-Atlantic

travel caused by the declaration of

war between England and Germany,

September 3, the American delegation to

the Congress was considerably delayed

in getting back. Only two failed ultimately

to return, Dr. and Mrs. F. W.

Tinney of the Division of Farm Crops

of the University of Wisconsin. They

were among about a dozen members of

the Congress who …

A Zygotic Lethal In Chromosome 1 Of Maize And Its Linkage With Neighboring Genes, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

A Bolivian maize

maize with mosaic red pericarp and cob, here designated by the symbol M-M, crossed with a local inbred strain of maize having white pericarp and cob, W-W, produced in F₁ 21 M-M and 28

W-W plants, not far from the I : I relation expected on the assumption that

the M-M parent was heterozygous for pericarp and cob color, M-M/W-W.

In F₂ and segregating F₃ cultures, however, there were 130 M-M and 64

W-W plants obviously a 2 : I instead of the 3 : I relation expected. Later cultures

increased these records to …

Relation Of The Differential Fertilization Genes, Ga Ga, To Certain Other Genes Of The Su-Tu Linkage Group Of Maize, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

The Ga, or “gamete” gene of maize can be studied only or principally by its disturbance of normal Mendelian ratios of contrasted characters differentiated by genes linked with it. The amount of this disturbance can be used as a measure of the intensity of linkage between Ga and other genes of the su-Tu group.

Disturbance of the 3:1 ratio of starchy, Su, to sugary, su, endosperm has been most studied. In one of the early papers on Mendelian inheritance, Correns (1902) reported that, although crosses between most starchy and sugary varieties gave an F₂ ratio of …

The A Series Of Allelomorphs In Relation To Pigmentation In Maize, R. A. Emerson, E. G. Anderson

Department of Agronomy and Horticulture: Faculty Publications

Introduction ... 503

The allelomorph A^b ... 504

The allelomorph a^p ... 505

Dominance ... 508

Summary ... 508

Literature Cited ... 509

The Frequency Of Somatic Mutation In Variegated Pericarp Of Maize, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

Some years ago (Emerson 1922) the writer announced that in F₂ of

certain crosses of variegated with colorless pericarp in maize the heterozygous

individuals changed to self color more frequently than did the homozygous

individuals of the same cultures. No “explanation” of this phenomenon

was then apparent, but later results, though still far from affording

an adequate solution of the problem, have furnished at least a working

hypothesis. The original unpublished paper, with minor modifications,

is given below, under the heading. “Somatic mutations in heterozygous

and in homozygous variegated pericarp.”

Control Of Flowering In Teosinte: Short-Day Treatment Brings Early Flowers, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

Attempts to force teosinte into flower in mid-summer, in order to facilitate hybridizing it with maize, have afforded considerable information concerning the flowering time of teosinte under diverse conditions. The possibility that some of this information may be of use to others suggests its publication. The paper is, therefore, to be considered as a help in the technique of teosinte and maize hybridization rather than a contribution ~to the solution of the physiological problems involved.

A Genetic View Of Sex Expression In The Flowering Plants, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

It seems a conservative statement to say that studies

of the past twenty years among animal forms have

tended increasingly to link the phenomena of sex inheritance

with the behavior of chromosomes. To this

result, cytology and genetics have contributed perhaps

almost equally. The number of forms in which

one sex is known to have a morphologically different

chromosome complex from the other sex are many.

That, with respect to the chromosomes, the female of

certain forms produces gametes of a single kind,

whereas the male produces two kinds, and that in

turn an egg fertilized by one kind of …

Pericarp Studies In Maize. I. The Inheritance Of Pericarp Colors, E. G. Anderson, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

Introduction ... 466

Nomenclature ... 467

Pigments present in colored pericarp ... 467

Factor relations of pericarp colors ... 468

Factor relations of red pericarp, P ... 468

Factor relations of cherry pericarp ... 471

Discussion and Summary ... 474

Literature Cited ... 475

Genetic Interrelations Of Two Andromonoecious Types Of Maize, Dwarf And Anther Ear, R. A. Emerson, Sterling H. Emerson

Department of Agronomy and Horticulture: Faculty Publications

Attention was called by Montgomery (1906)to the occasional appearance

of perfect flowers in the staminate inflorescence of maize and similar

cases were reported by Kempton (1913). Montgomery (1911) described

with illustrations a true-breeding type of semi-dwarf dent maize, the ears

of which were perfect-flowered. Perfect-flowered maize was described

and illustrated also by Blaringhem (1908, pp. 180-183). East and

Hayes (1911, pp. 13, 14) noted and illustrated a perfect-flowered sweet

corn. Weatherwax (1916, 1917) showed that typically pistillate

flowers of maize exhibit in microscopic sections the rudiments of stamens

and that staminate flowers show rudiments of pistils.

The Relative Frequency Of Crossing Over In Microspore And In Megaspore Development In Maize, R. A. Emerson, C. B. Hutchison

Department of Agronomy and Horticulture: Faculty Publications

One of the early developments in the study of linkage in Drosophila was the discovery that the phenomenon of crossing over is confined to the female sex (Morgan 1912). The fact that no crossing over occurs in the male Drosophila holds true not only for sex-linked genes but for factors in the autosomes as well and is so well established that it affords a most convenient method of determining to which of the different linkage groups a new factor belongs.

The same phenomenon, but with the sexes reversed, obtains in the silkworm moth. Tanaka (1914, 1915) has found from back-cross …

Heritable Characters Of Maize: Ix. Crinkly Leaf, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

In 1910 a strain of dent corn obtained at the National Corn Exposition held at Omaha was crossed with a strain of flint corn obtained from the Department of Agronomy of the University of Nebraska. The F₁ plants of this cross were normal and no abnormalities had been observed in the parent strains. But since the latter had not been subjected to self-pollination, there is no assurance that one or other of them did not have in it the character to be described here. In the F₂ generation of this cross there occurred a tpe of plant that …

Bulletin No 80 - Cultivation Of Sugar Beet, Percy G. Wicken

Bulletins 1 - 2999

The beet belongs to the Chenopodiaceae or Salsolaceae, an order of plants which include among them many of the native saltbushes. The sugar beet (Beta vuigaris crassa) is supposed to have been developed from the wild beet (Beta vulgaris maritima), which is indigenous to the countries along the coast of Southern Europe. it is a biennial plant—that is, of two years' duration. The first year it produces a full-sized root, the second year it produces its seeds, and then dies off. Sometimes a few plants Produce seed the first year, but this is only on account of the seed being …

Heritable Characters Of Maize Ii.-Pistillate Flowered Maize Plants, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

In the "freak"

class at the Annual

Corn Show held at Lincoln, Nebraska,

in the winter of 1913-14,

there was exhibited a corn tassel

with a heavy setting of seeds. A few

seeds are not infrequently found in the

staminate inflorescence of maize, particularly

in pod com, and tillers of various

corn varieties often end in ears instead

of in tassels or have tassels, the central

spikes of which are ear like. The freak

exhibited at the com show, however,

was a large. much branched affair.

wholly tassel-like in form except for the

fact that it bore a heavy crop …

Genetical Studies Of Variegated Pericarp In Maize, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

Two years ago there were presented some results of a study of the inheritance of self pattern in the pericarp of maize seeds, occurring as a sporophytic2 variation in variegated ears (EMERSON1 914). Further results, in entire accord with those previously reported, have now been obtained. In addition, data bearing upon new phases of the problem are also available.

The chief results reported in the earlier paper were the following: ( I ) The more nearly self-colored the pericarp of any seed of a variegated ear, the more likely is the progeny of that seed to produce a self-colored ear …

The Inheritance Of A Recurring Somatic Variation In Variegated Ears Of Maize, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

The inheritance of variegation has special interest and importance in genetics. It is with forms of variegation that the only two certainly known cases of non-Mendelian inheritance have had to do. I refer to Baur's experiments with Pelargonium, in which crosses of green-leaved and white-leaved forms exhibited somatic segregations in F₁ that bred true in later generations, and to Correns 's work with Mirabilis, which showed green and white leaf color, to be inherited through the mother only. De Vries's con- ception of "ever-sporting" varieties was apparently founded largely upon the behavior of variegated flowers in pedigree …

Multiple Factors Vs. "Golden Mean" In Size Inheritance, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

Groth's preliminary note on the "golden mean" in the inheritance of sizes in SCIENCE of April 17, 1914, pp. 581-584, deserves the attention of geneticists. Its publication is of such recent date that I need only call attention to one or two points that seem to me of particular moment.

In brief, Groth's hypothesis is that the mode

of inheritance in F_l not only of surfaces and

volumes, but also of linear dimensions is to be

expressed by √ab rather than by a + b /2

where a and b are parent sizes. The hypothesis

is based upon …

Shorter Articles And Discussion Simplified Mendelian Formulae, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

I was somewhat surprised by 'Morgan's and Castle's suggestions for a simplification of Mendelian formulae. My surprise was not occasioned so much by the forms these suggestions took as by the fact that any pronounced changes were deemed necessary. I had not only employed the usual formula in my own work but had found no difficulty worth mentioning in understanding the formula used by most other workers in Mendelian fields. My experience with students in elementary courses in genetics had not prepared me for the idea that such formula were particularly difficult. Nevertheless I believe in simplifying the formulae if …

The Possible Origin Of Mutations In Somatic Cells, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

That mutations are accompanied by some change in the germ-plasm is, I take it, indisputable. Have we, however, any reason to suppose that the change takes place within the germ cells? I am not sure, as a matter of fact, that genetists in general regard the gametes as the place of origin of mutations. It is true, however, that experiments in the artificial production of mutations in plants have been limited largely to treatments of the ovaries from about the time of the reduction division to about the time of fertilization. This suggests a belief on the part of investigators …

Shorter Articles And Reports: The Simultaneous Modification Of Distinct Mendelian Factors, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

In another paper on the inheritance of a recurring somatic variation in variegated ears of maize, it was shown that the amount of red color developed in the pericarp of variegated seeds bears a definite relation to the development of color in the progeny of such seeds. The relation is such that the more color there is in the pericarp of the seeds planted the more likely are they to produce plants with wholly self-red ears and correspondingly the less likely to produce plants with variegated ears. Self-red ears thus produced behave just as if they were hybrids between self-red …

The Unexpected Occurrence Of Aleurone Colors In F2 Of A Cross Between Non-Colored Varieties Of Maize, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

Before the Mendelian methods of analysis became available, considerable wonder would doubtless have been excited by the "mysterious" appearance in F₂ of one colored grain-purple or red-to every five or six white ones in case of a maize cross, both parents and F, of which had only white grains. An occurrence of this sort has recently been noted in one of my maize cultures and the F2 numbers are explained here as a trihybrid or tetrahybrid ratio. The crosses in question were made primarily for a study of size inheritance and fairly large numbers have been grown. The varieties …

Discussion And Correspondence Coupling Vs. Random Segregation, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

To the editor of science: The suggestion offered by Morgan, in SCIENCE of September 22, to account for the coupling and repulsion of factors for various characters in inheritance in such forms as Abraxas, Drosophila, fowls, sweet peas, etc., incites this note.

Briefly Morgan's hypothesis is (1) that the materials representing factors that couple are "near together in a linear series" in the chromosomes; (2) that, when pairs of parental chromosomes conjugate, "like regions stand opposed "; (3) that "homologous chromosomes twist around each other," but that the separation of chromosomes is in a single "plane"; (4) that, thereby the …

The Inheritance Of Sizes And Shapes In Plants, R. A. Emerson

Department of Agronomy and Horticulture: Faculty Publications

Some years ago Lock reported a cross of a tall race of maize with a shorter race which produced an intermediate height in F₁ and exhibited no segregation in F₂ when crossed back with one of the parents. Castle's results with rabbits are very similar to those of Lock with maize. Castle summarizes his results in part as follows:

A cross between rabbits differing in ear-length produces offspring with ears of intermediate length, varying about the mean of the parental ear-lengths. . . . A study of the offspring of the primary cross-breds shows the blend of the …

Observations Of The Adaptation Of The Leaves Of Kalmia Latifolia To Environment, Grace Ellen Wilson

Student and Lippitt Prize Essays

Samples taken from the plant for observation are from two different locations (high dry land with full sun/low moisture and a swamp) and show that the leaves of the plant flourish more in sunlight than in dark, swamp areas.