Selfed Lines Research Articles

Genetic variation of colchicine induced and spontaneous doubled haploids obtained by anther culture of an inbred tobacco.

Effects of colchicine used for chromosome doubling of haploid plants were examined as a possible cause for the genetic variation among anther-derived doubled haploid lines of an inbred tobacco (Nicotiana tabacum L.). Colchicine induced doubled haploid lines (C-DH) and spontaneous doubled haploid lines (S-DH) were developed and their agronomic traits were compared with those of the selfed lines of the parental plant used for the anther culture. S-DH exhibited as great quantitative variability within the family as C-DH did. In each case, the direction of the changes was towards low productivity ; reduction of plant height and leaf size. Some doubled haploid lines were revealed to have nornicotine, another type of the alkaloids, whereas all of the selfed lines of the source plant for anther culture had normal nicotine as the major alkaloid. This change in the alkaloid type was found in the plantlets before the colchicine treatment was applied. In addition, colchicine treatment of seed-derived diploid seedlings did not produce the nornicotine-type plantlets. These findings indicate that the colchicine treatment contributed little to the genetic variation of doubled haploid lines.

FEASIBILITY OF PRODUCTION OF COMMERCIAL HYBRIDS IN REED CANARYGRASS, Phalaris arundinacea L., USING A YELLOW-SEEDED MUTANT

A yellow-seeded mutant of reed canarygrass resulting from close breeding was used to produce F1 hybrids with normal black-seeded strains. The vigor of the yellow-seeded parent was below that of standard cultivars but seed yield was significantly higher. Forage yields of hybrids from the free interpollination with black-seeded strains were equal to, but not above, those of recommended cultivars. A high degree of effective hybridization (80% or more) was obtained when sib lines, selfed lines, or synthetics of the yellow-seeded mutant were grown in alternate rows with black-seeded strains. Alternate three-row (3 m) groups of parents in the hybrid crossing block were convenient for machine harvesting of seed and resulted in good hybridization.Key words: Reed canarygrass, heterosis, incompatibility, seed production, pollination

Stability of agronomic traits in cytoplasmic male sterile tobacco obtained by protoplast fusion.

Agronomic performances of the male sterile tobacco (Nicotiana tabacum cv. Consolation 402) obtained by protoplast fusion between Consolation 402 and X-irradiated N.debneyi were evaluated. A majority of the male sterile lines in the BC1 generation exhibited almost equivalent field performances to the selfed lines of normal fertile Consolation 402, and stable performances of these male sterile lines were also recorded in the following generation. In the BCI generation, however, there were a few lines showing late maturity and smaller stature. These lines did not carry a specific type of chloroplast genom.e, thus suggesting little participation of chloroplast genomes in the observed deviations. Also, such deviated traits appeared to be recovered in the subsequent generations of backcrosses. This indicates that the deviated traits are resulted from mutational events in the nuclear genome during in vitro culture. None of the male sterile lines segregeted any fertile plants. The observed stability of fusion-derived male sterile tobacco both in agronomic traits and in the male sterility indicates that the protoplast fusion method can be incorporated into a practical breeding program as an alternative for obtalning male sterile tobacco.

Relationship Between GA Application and Phyllomorph Length in Streptocarpus

Abstract Three cultivars and 3 selfed lines of Streptocarpus × hybridus Voss plants proved to be highly variable via cluster analysis. Yet 5 of the 6 populations examined showed a significant, negative, linear correlation between flowering and phyllomorph length at the time of treatment with 25 μg GA4+7. There was no treatment effect on peduncle length or the time span separating flowering of the first and 2nd, 2nd and 3rd, or first and 3rd inflorescences.

Screening and selection of pearl millet for root associated bacterial nitrogen fixation

There are several reports of genotypic variability in grass species for their ability to achieve associations with N 2-fixing soil bacteria. These findings imply that plant breeding may be useful in enhancing these associations and thereby making available plant germplasms needed for agronomic and physiological studies of associative N 2-fixation in grasses. When the N 2-fixing bacterium Azospirillum brasilense (strain JM 125) was used as inoculum, differences were found among selfed lines of pearl millet ( Pennisetum americanum (L.) K. Shum.) for an ability to support bacterial acetylene reduction activity (ARA) when assayed in enclosed seedling agar tubes. These lines were selfed again or hybridized. Although line to line discrepancies were seen, the ARA of these lines and hybrids when categorized into high or low groups matched the activity of their original parental lines. Also, the selfed and hybrid groups obtained from high ARA lines supported higher numbers of bacteria and lost greater quantities of 14C from their roots than did those groups obtained from low ARA lines. Two of these lines, one having high ARA and one having low ARA, were grown in soil in the greenhouse and were found to differ in their respective ability to support ARA by the soil N 2-fixing microbes. However, overall ARA of the high line was quite low unless analyzed in a hydroponic culture system at low O 2 tensions.

Comparison of genetic variability among anther-derived and ovule-derived doubled haploid lines of tobacco.

This study was conducted to obtain information on the causes of variation of anther-derived doubled haploid lines from a inbred cultivar of tobacco (Nicotiana tabacum). From a spontaneous doubled haploid lines of androgenetic origin of tobacco, an experimental series of doubled haploid lines was raised through anther culture or induced parthenogenesis. The field test of 38 anther-derived and 12 ovule-derived doubled lines along with 17 lines of the selfed parent revealed considerable variations among the anthel-derived lines both in quantitative and qualitative characters. On the other hand, all the ovule-derived lines, some of which were doubled by colchicine treatment while the others were doubled spontaneously, were not different from the selfed lines of the parental plant for the characters measured. No cytoplasmic effects were detected in the reciprocal crosses between anther-derived doubled haploid lines possessing variations and the parental line. These results indicate that the variations observed among doubled haploid lines of androgenetic origin were due to the mutations of nuclear genes in the course of androgenesis.

Female Sterility in an Indica-Japonica Cross of Rice

日本のイネ品種`藤坂5号'を母とし，インドネシア品種`Tjina'を父とする雑種F1に藤坂5号を4回戻し交雑した後代系統の中から，遺伝様式の単純な雌性不稔が見出された。雑種系統における種子稔性の分離に2遺伝子が関与し，この二重劣性ホモで雌性不稔が生ずると推定された。雌性不稔個体では，正常な花粉が生ずるが，胚のうが形成されなかった。しかし，1穂に2ないし3粒の頴花が結実し，この種子によって雌性不稔は次代に伝達された。

INDUCTION OF TWO MUTANTS IN BIRDSFOOT TREFOIL (Lotus corniculatus) BY X-RAYS AND CHEMICAL MUTAGENS

The mutagenic effects of X-rays, ethyl methanesulfonate (EMS), 8-ethoxycaffeine (EOC), N-hydroxyurea (HU) and 2-aminopurine (2AP) on seed treatment of birdsfoot trefoil (Lotus corniculatus L. ’Mirabel’) were assessed over four generations. Mutants were recovered in the M2, M3 and M4 generations from selfed lines, from crosses derived from selfed lines and from open pollination lines. Mutant plants exhibiting vestigial floret character were recovered from X-ray, EMS, EOC and HU treatments. Mutant chlorotica plants were obtained from EMS treatment only. No mutants were recovered from 2AP treatment, EMS, the most effective mutagen, produced nine vestigial floret and 12 chlorotica mutants. Mutants were obtained from only one exposure of X-rays (12 krad). There was evidence for preferential elimination of gametes. The chlorotica and vestigial floret mutants were inherited as tetrasomic recessives. Mutation frequencies of 0.4–3.1% in a tetrasomic background are indicative of the effectiveness of EMS in birdsfoot trefoil.

Study of intraclonal conjugation in Chilodonelia steini. Evidence of abortive conjugation

AbstractMating and conjugation in the ciliate Chilodonella steini has been examined. Only intraclonal conjugation has been found thus far in this species. Stable opposite mating types have not been observed, even after extensive single cell isolations and the observation of cell lines following two consecutive generations of inbreeding. Following intraclonal conjugation, two kinds of selfing lines appear: 1) lines that enter long immaturity periods, 2) lines that do not enter immaturity at all, but maintain a permanent ability to pair. These lines do not yield immature progeny after a subsequent conjugation. Immature lines result from true conjugation as expected, whereas those lines that do not enter immaturity result from an abortive process. During normal conjugation the new macronuclear anlagen develop and the old macronucleus is resorbed. During abortive conjugation the new macronuclear anlagen also develop but the old macronucleus is not resorbed. Eventually the old macronucleus, instead of the new one, divides to provide a somatic nucleus for the progeny. Thus macronuclear retention occurs in some lines of Ch. steini similar to that observed in senescent lines of Tetrahymena thermophila.

Factors Affecting Efficiency of Hybridization and Selection in Cassava1

An analysis of genetic variability in several populations of cassava (Manihot esculenta Crantz) revealed that it is a highly heterozygous species. This species is monoecious, and no genetic or physiological barrier to prevent self‐fertilization was found. Both self and crosspollination occurred naturally. Thirty meters of separation between populations was sufficient to ensure genetic isolation. The average yield of selfed lines was about half the average yield of the parental genotypes. The degree of inbreeding depression varied greatly in different genotypes. Average yields of populations derived from open pollination of male‐fertile genotypes were lower than the average yields of populations derived from the controlled pollinations of the same genotypes. In male.sterile genotypes, no yield difference was observed between the open‐pollinated progenies and those from the controlled pollinations. Controlled pollinations are recommended as a general method of hybridization in cassava. If a breeder chooses open pollinations, use of male steriles is recommended. Correlations of root yield and harvest index (proportion of root weight to total plant weight) between the seedling plant and the same genotype when planted with stem cuttings were high. Root yield in a single‐row trial was not correlated with root yield in a replicated population trial, but harvest index in the single.row trial was significantly correlated with the root yield in the population trial. Intergenotypic competition caused a yield difference of more than 100%, but there was no significance in harvest‐index difference. Harvest index was highly heritable, and it is an excellent selection character.

A Rapid Method Based on Butanol Extraction for Selecting High‐Lysine Maize (Zea mays L.)1

Whole kernel samples from 48 selfed lines (S2, S3) of maize (Zea mays L.) were obtained from crosses involving normal and the mutant opaque‐2. Kernels from these samples were classified as translucent, semitranslucent, and opaque in appearance. All were treated with watersaturated n‐butanol at room temperature. The extraction resulted in losses of nitrogen ranging from 0 to 40%. The nitrogen compounds extracted were nearly free of lysine. The proportion of butanol‐insoluble nitrogen to total nitrogen was closely correlated with lysine content of the protein, with an r value of .817. Similarly, the insoluble nitrogen was closely correlated (r = .847) with the lysine content on a whole‐kernel basis. Since the method requires only the simple procedures of nitrogen determination and butanol extraction, it should be very suitable for screening a large number of maize samples for high lysine.

Potato clones remain free from leaf roll virus after repeated attempts to infect them

Potato seedlings grown from true seed were screened for resistance to leaf roll virus. Infected seedlings were discarded, and the screening process was repeated for four subsequent tuber generations. Forty-one of an original 717 clones (six crosses and three selfed lines) remained free from the virus. Challenge inoculations were made with aphids,Myzus persicae (Sulz.), that had been colonized on infected excised leaves ofPhysalis floridana Rydb. Recovery tests were attempted with non-viru-liferous aphids that were tested on healthyP. floridana. In comparative tests, more clones remained free from the virus among progeny of the cross F5569×F4896 and of a self of the Katahdin variety, than among any other progeny tested.

Breeding Behavior of Mite-Resistant Strawberries1

Abstract Backcrosses and outcrosses of mite resistant strawberry selections and combinations of resistant selfed lines were made. Backcrosses to the resistant parents resulted in intermediate progeny means but they were closer to that of the less resistant parent. Backcrosses to the susceptible parent also resulted in intermediate progeny means but they were close to that of the more resistant parent. Outcrosses gave progenies similar to those of backcrosses but with less spread in resistance. Crosses of certain resistant selfed selections showed almost complete dominance for mite resistance.

Effect of Selecting within Selfed Lines on the Yield and Other Characters of Cotton1

Agronomy JournalVolume 45, Issue 7 p. 275-279 Article Effect of Selecting within Selfed Lines on the Yield and Other Characters of Cotton1 D. M. Simpson, D. M. SimpsonSearch for more papers by this authorE. N. Duncan, E. N. Duncan Agronomist and Bio. Science Aid, respectively.Search for more papers by this author D. M. Simpson, D. M. SimpsonSearch for more papers by this authorE. N. Duncan, E. N. Duncan Agronomist and Bio. Science Aid, respectively.Search for more papers by this author First published: 01 July 1953 https://doi.org/10.2134/agronj1953.00021962004500070001xCitations: 3 1 Contribution from Division of Cotton and Other Fiber Crops and Diseases, Bureau of Plant Industry, Soils, and Agricultural Engineering, Agricultural Research Administration, U. S. Dept. of Agriculture, and the Tennessee Agricultural Experiment Station, Knoxville, Tennessee, cooperating. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume45, Issue7July 1953Pages 275-279 RelatedInformation

Inheritance of Chlorophyll in F1 Grosses Made Reciprocally Between Selfed Lines of Corn.

SummaryThese studies show that maternal inheritance of chlorophylls as measured by a series of crosses made reciprocally between high and low chlorophyll inbred lines of corn is not significant, an...

The Breeding of Improved Selfed Lines of Corn1

Agronomy JournalVolume 31, Issue 8 p. 710-724 Article The Breeding of Improved Selfed Lines of Corn1 H. K. Hayes, H. K. HayesSearch for more papers by this authorI. J. Johnson, I. J. Johnson Chief and Associate Professor, respectively.Search for more papers by this author H. K. Hayes, H. K. HayesSearch for more papers by this authorI. J. Johnson, I. J. Johnson Chief and Associate Professor, respectively.Search for more papers by this author First published: 01 August 1939 https://doi.org/10.2134/agronj1939.00021962003100080008xCitations: 32 1 Contribution from the Division of Agronomy and Plant Genetics, University of Minnesota, St. Paul, Minn. Paper No. 1709 of the Journal Series, Minnesota Agricultural Experiment Station. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume31, Issue8August 1939Pages 710-724 RelatedInformation

The Relationship between the Origin of Selfed Lines of Corn and Their Value in Hybrid Combination1

The Relationship between the Origin of Selfed Lines of Corn and Their Value in Hybrid Combination¹

Yield and Composition of Eared and Earless Maize Plants in a Selfed Line Segregating Barren Stalks1

Agronomy JournalVolume 28, Issue 2 p. 85-91 Article Yield and Composition of Eared and Earless Maize Plants in a Selfed Line Segregating Barren Stalks1 R. J. Garber, R. J. GarberSearch for more papers by this authorR. B. Dustman, R. B. DustmanSearch for more papers by this authorC. R. Burnham, C. R. Burnham Agronomist, Agricultural Chemist, and Assistant Geneticist, respectively.Search for more papers by this author R. J. Garber, R. J. GarberSearch for more papers by this authorR. B. Dustman, R. B. DustmanSearch for more papers by this authorC. R. Burnham, C. R. Burnham Agronomist, Agricultural Chemist, and Assistant Geneticist, respectively.Search for more papers by this author First published: 01 February 1936 https://doi.org/10.2134/agronj1936.00021962002800020001x 1 Contribution from the Department of Agronomy and Genetics and the Department of Agricultural Chemistry, West Virginia Agricultural Experiment Station, Morgantown, W. Va. Published with the approval of the Director, West Virginia Agricultural Experiment Station, as Scientific Paper No. 158. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume28, Issue2February 1936Pages 85-91 RelatedInformation

The Comparative Root Development of Selfed Lines of Corn and Their F1 and F2 Hybrids1

The Comparative Root Development of Selfed Lines of Corn and Their F1 and F2 Hybrids¹

Chlorophyll Content as an Index of the Productive Capacity of Selfed Lines of Corn and Their Hybrids1

Chlorophyll Content as an Index of the Productive Capacity of Selfed Lines of Corn and Their Hybrids¹