TUS INHERITANCE OF RESISTANCE TO ÜSTILAGO NUDA (JENS.) K. AND S ,, RACE I, IN BARLEY By Voustapha Ibrahim Zeidan A THESIS Submitted to the School of Graduate Studies of Michigan State College of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Botany and Plant Pathology 195:3 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Tî-îE INHERITANCE OF RESISTANCE TO USTILAGO NUDA (JENS.) K. MID S . , RACE I , IN BARLEY By Houstapha Ibrahim Zeidan AN ABSTRACT Submitted to tbe School of Graduate Studies of Michigan State College of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Depatment of Botany and Plant Pathology 1953 Approved Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ABSTRACT Barley has been knoiim for centuries as a cultivated plant used for making bread and as feed for animals. This crop is attacked by many diseases ’which become imnortant factors in decreasing yields. Loose smut caused by Ustilago nuda (Jens.) K. and S. is one of these diseases. Its control by the hot water treatment, modified hot water treatment and by organic compounds is unsatisfactory and hazardous. Consequently the use of resistant varieties is the effective method. The present investigation was concerned with the inheritance of resistance to Ustilago nuda (Jens.) K. and S., race I, the genetic con­ stitution of. the parental varieties and the relationship between factors for resistance and those for morphological characteristics. Four non-commercial varieties (Jet, Anoidium, Harlan, Ogalitsu) resistant to loose, smut disease were crossed into all possible combina­ tions: Jet X Harlan, Jet x Anoidium, Jet x Ogalitsu, Harlan x Ogalitsu, Harlan x Anoidium, and Ogalitsu x Anoidium. Jet has a two-rowed head, naked seeds, rough awns, a black lemma and pericarp. The others have six-rowed head, covered seeds, white lemma and pericarp. Harlan and Otalitsu have semi—smooth awns, while the awns of Anoidium are smooth. The florets of one or two heads of plants were inoculated. One or two drops of fresh snore suspension ’.vere introduced into each floret by means of the "needle" method. The classification of families which represented the Fg plants, into resistant, segregating and suscep­ tible groups was made according to the percentages of infection. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. The inheritance of resistance to Ustilago nuda (Jens.) K. and S., race I, in the crosses Jet x Harlan, Harlan x Ogalitsu, Ogalitsu x Anoidium, is explained by two gene pairs acting in duplicate dominant epistatic condition. The two genes were found to be different and independently inherited. Thus, each parent possesses one dominant gene pair for resistance. One gene difference was found between two-rowed vs. six—rowed head, covered vs. naked seeds, black vs. white lemma and pericarp in the hybrids of Jet x Harlan. Also, no linkage was found to exist between factors for resistance and those for the above mentioned moiphological characteristics. The inheritance of resistance in the cross Jet x Anoidium and Jet x Ogalitsu was not studied, because of the inadequate number of families. In the cross Harlan x Anoidium, the resistance was interpreted in terms of two gene pairs exhibiting dominant and recessive epistasis. The genes also were different and independently inherited. The expected ratio was 1^:1 but the observed ratio was 13:3. However, the excess of susceptible families could be interpreted by the occurrence of fluctuation in some genotypes, which might be due to a change in the expression of the resistance and the susceptibility. This change might be influenced by the environment. Thus, each parent also possessed one dominant gene. Four genes were found to govern the resistance in the four varieties used in this investigation. These genes were found to be different and to be independently inherited. There was no evidence of linkage between resistance and morphological characters. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ACKNO'ArLEDGl\ffiMTS The author wishes to express bis sincere gratitude to Doctor John R. Vaughn and Doctor Kenneth J. Frey for their effective guidance and criticis'n in carrying out this investigation. He is also greatly indebted to Doctor Villia'n 3, Drew for his kind and valuable advice and criticisoi along the preparation of this ■oanuscript, The author wishes to thank Doctor Constantine J. Alexopoulos, Doctor Eldon E, Down and Doctor Jesse E, Muncie for their careful criticism of this thesis. Finally, he deeply appreciates the people of Lebanon for the financial help by which he was assisted in completing his training in the United States of America. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. TABLE OF CONTENTS I. INTRODUCTION................................................. 1 A. Economie importance of b a r l e y ............................ 1 B . Economie importance of the di s e a s e ................... 1 C . Practical control m e t h o d ......... 2 D. Objectives of the study ..................... 2 II. REVIEW OF L I T E R A T U R E ........................................... '3 A. History of loose smut organism Ustilago nuda (Jens.) K. and Srace I ........................................... 3 B. Inheritance of resistance to Ustilago nuda (Jens.) K. and S ...................................................... ^ C . Inheritance of agronomic characters........................ 7 1. Two-rowed vs. six—rowed heads .............. 7 2. Naked vs. covered s e e d s .......... 9 3. Rough awns vs. smooth awns , .........................10 U« Black lemma and pericarp vs. white lemma and pericarp . 11 D. Linkage studies .......... 11 E. Infection of hybrid progenies.............................. 12 III. MATERIALS AND T^ETHODS........................................... lU IV. EXPERIMENTAL RESULTS ........................................... 21 A. Study of the reaction of the parental varieties Jet, Anoidium, Harlan and Ogalitsu to loose smut infection . 21 B. 'Study of the inheritance of resistance in hybrids............21 1. Jet X H a r l a n ............ 21 2. Jet X Anoidium .........................................26 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 3, Jet X Ogalitsu .................................... .. 28 h» Harlan x Ogalitsu.......................................28 5» Harlan x Anoidium.................................. 31 6. Ogalitsu X Anoidium.................................... 33 C. Study of the inheritance of agronomic c h a r a c t e r s ...........37 1. Two-rowed vs. six-rowed h e a d s .......................... 37 2 • Hulled vs. naked seeds ............................ UO 3. Rough awns vs. smooth awns ........................ Ul U. Black lemma and pericarp vs. white lemma and pericarp • U3 D* Study of the linkage r e l a t i o n s .............. ............ 1. Resistance vs. susceptibility with two—rowed vs. six-rowed h e a d s ....................................... 2. Resistance vs. susceptibility with hulled vs. naked seeds ............................................... U6 3. Resistance vs. susceptibility with black lemma and pericarp vs. white lemma and pericarp................ U7 V. SELECTION....................................................... k9 VI. DISCUSSION ..................................................... $0 VII. sumuiRY .......... 55 LITERATURE C I T E D ................................................... 57 APPENDIX ........................................................... 62 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. INTRODUCTION The barley crop has been known for centuries as a cultivated plant for making bread and as a feed for animals. In addition, it is also used today in nanufacturing items for human consumption: breakfast food, flour.and spiritous liquors. Barley is grown under a wide range of environmental conditions in many countries of Asia, Europe, as well as in the United States of America. In the United States, barley production is concentrated in the mid­ west states: North Dakota, Minnesota, South Dakota, Wisconsin, Michigan, Iowa, Illinois, and in the far west in California. It was reported that California was the leading barley producer in 19^1. Michigan during the same year produced 3,876,000 bushels of barley grain having a revenue of oU,692,000 which amount gives barley fourth rank after corn, wheat, and oats in crop income (1, 10, 39). It is true that barley does not occupy first place among the small grains but it is an important crop, especially for animal consumption. Barley can compete with oats for this purpose, and in many places in the United States barley is more profitable and produces more bushels per acre than oats. Besides these benefits, barley is used for breaking new soil (23). Its early maturation allows it to be cut before many other species which have mature seed. It is also used for old lands which have become too poor for producing good crops of wheat or com. ' Barley is affected by manj»" diseases which decrease its production quantitative!:/- and qualitatively. Important among these barley diseases are the smut