Thesis (Ph. D.)--University of Michigan, 1931. / Cover title. Published also as Michigan Agricultural experiment station Technical bulletin no. 118, January, 1932. Bibliography: p. 63-67.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1949. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves [38]-39).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1950. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 80-81).

Survey of crops of common bean (Phaseolus vulgaris L.) in Sonora, Mexico revealed the presence of two isometric viruses and one flexuous rod virus on the basis of host reaction, particle morphology, serology and physico-chemical properties. The isometric viruses were identified as Bean Southern Mosaic Virus (BSMV) and Cowpea Chlorotic Mottle Virus (CCMV); the flexuous rod virus was identified as Bean Common Mosaic Virus (BCMV). Using bean cultivar differentials, two strains of the potyvirus BCMV were identified, NY-15 and a previously undescribed strain designated YV-1. Host range, serological tests, and RNA electrophoresis indicated that the Sonoran BSMV cultures are similar to BSMV-strain A. Serology and RNA-electrophoresis indicated that the Sonoran CCMV isolates are identical to CCMV-strain A. BSMV and CCMV were always isolated as a mixture from seed lots and from field collected bean tissue. BCMV occurred alone or in mixed infections with BSMV and CCMV. BCMV was seed transmitted with an average efficiency of 58 percent. The BSMV-CCMV mixture was transmitted with an efficiency of 6 percent. BSMV and CCMV were seed transmitted together, but separate transmission of BSMV or CCMV was not detected. Commercial seed lots from two major bean growing regions of Sonora (Hermosillo Coast, Sonora River) were contaminated with the BSMV-CCMV mixture but not with BCMV. The average contamination level was 13 percent. Two common weeds present in Sonoran agricultural areas were found to be potential alternate hosts of CCMV. Both Sisymbrium irio L. and Melilotus indica L. were infected systemically, although the infection in M. indica was latent. Potential losses due to Sonoran bean viruses were measured in greenhouse experiments with the cultivar Pinto 111. BCMV strains caused a 29.4 to 60.1% reduction, whereas BSMV-CCMV mixtures induced a 22.5 to 74.6% yield reduction. A synergism occurred between the BSMV-CCMV mixture and BCMV resulting in more severe symptoms and a yield reduction of 92.7%. Synergistic effects were also observed between BSMV and CCMV. Actual yield reduction resulted from impaired flower production and, consequently, reduced pod production. Significant effects on plant tissue production, flower fertilization and seed quality were not observed. Cowpea chlorotic mottle virus infected mung bean (Vigna radiata (L.) Wilczek) a previously unreported host. Infection of mung bean by BSMV was only possible when CCMV was present in the inoculum. Both BSMV and CCMV could be isolated from symptomatic plants infected with the BSMV-CCMV mixture, however, symptoms on mung bean were unchanged from infection by CCMV alone.

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Thesis (M. Sc.)--University of Hong Kong, 1969. / Typewritten.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1948. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves [82]-84).

A technique involving Restriction Fragment Length Polymorphism (RFLP) was used to observe the DNA fragment polymorphism between a bean cultivar with I/I genotype and a bean cultivar with i/i genotype. The I gene encodes immunity to bean common mosaic virus (BCMV).

Call number: LD2668 .T4 1978 R35 / Master of Science

Double infection by cowpea strains of southern bean mosaic virus (CP-SBMV) and of tobacco mosaic virus (CP-TMV) caused additive growth reductions in California blackeye cowpea. Plant height, weight and numbers of seed and pods were significantly reduced by double infection and by CP-TMV single infection compared to healthy and CP-SBMV-sing 1 y infected plants. Singly and doubly inoculated California blackeye cowpea plants developed CP-SBMV symptoms on the primary leaves, but CP-SBMV symptoms in doubly infected trifoliates were masked by CP-TMV symptoms. CP-TMV symptoms did not mask CP-SBMV symptoms in systemically infected trifoliate leaves of another cowpea variety, V45-Bots. CP-TMV infection conditioned systemic infection of V45~Bots by CP-SBMV, as indicated by infectivity,serology and analytical sucrose density gradient centrifugation. CP-TMV also induced susceptibility of Pinto to infection by CP-SBMV, as ascertained by infectivity, immunodiffusion and electron microscopy. Analytical sucrose density gradient centrifugation measurements demonstrated that in doubly inoculated primary leaves of California blackeye cowpea CP-SBMV and CP-TMV were synthesized less than in the same leaves singly inoculated. CP-SBMV synthesis in trifoliate leaves, following simultaneous inoculations of primary leaves, was enhanced 5 times that in singly infected trifoliate leaves, whereas CP-TMV synthesis was not greatly affected. When CP-TMV preceded CP-SBMV in the primary leaves by 2k and 72 hr CP-SBMV synthesis was enhanced more in trifoliate leaves that were undifferentiated at the time of inoculation than in those of plants simultaneously inoculated. When CP-TMV preceded CP-SBMV into preformed 3rd trifoliate leaves by 22 hr, the ratio of CP-SBMV concentration in doubly infected tissue to that in singly infected tissue was 2.7 versus 1.9 when both viruses arrived simultaneously at these leaves. When either virus preceded the other by 72 hr into preformed 3rd trifoliate leaves the synthesis of the challenging virus was greatly retarded. CP-SBMV synthesis was also enhanced by CP-TMV infection under differential temperature synchronous system of infection. Although virions of both viruses were detected in the same cell no genomic masking was detected by infectivity neutralization test. It is theorized that CP-TMV infection predisposes the host cells to infection by CP-SBMV and thus the enhanced synthesis of CP-SBMV. The effect of CP-TMV infection on CP-SBMV synthesis in cowpea seems to be a physiological one. CP-SBMV, but not CP-TMV, was transmitted through planted seed and decontaminated embryos of California blackeye cowpea. Buffer extracts made from decontaminated embryos also were infectious for CP-SBMV. Seed coats contained both viruses. Double infection of California blackeye cowpea decreased seed transmission of CP-SBMV from 13-5 to 7.6%. Buffer extracts of healthy seed were inhibitory to infectivity of both viruses. Germination of seed reduced infectivity of CP-SBMV in the seed coats, but not of CP-TMV. It is also concluded that seed transmission of CP-SBMV is a result of embryo infection rather than contamination with virus in the seed coats. / Land and Food Systems, Faculty of / Graduate