Diversity among nucellar-seedling lines of Satsuma mandarin and differences from the parental old line
AuthorsHoward B. Frost
James W. Cameron
Robert K. Soost
Authors AffiliationsHoward B. Frost was Associate Plant Breeder, Emeritus, in the Experiment Station, Riverside; James W. Cameron was Associate Geneticist in the Experiment Station, Riverside; Robert K. Soost was Associate Geneticist in the Experiment Station, Riverside.
Hilgardia 27(7):201-222. DOI:10.3733/hilg.v27n07p201. October 1957.
Nucellar embryos are produced asexually, from somatic cells of the nucellus. Usually, therefore, nucellar seedlings reproduce the genotype of the seed parent. Nongenetic differences from the seed parent occur as transient juvenile characteristics, and also sometimes result from elimination of disease viruses.
Budded descendants of nucellar seedlings of one seed-parent Satsuma tree have been studied in two propagated generations, in eighteen crop years. Trees of the first generation, budded directly from different nucellar seedlings, commonly differed so consistently in fruit shape as to indicate considerable probability of genetic diversity.
From two of these budded trees, which differed in fruit shape and also in leaf size, trees were budded for small plots. These plots differed significantly in tree form and leaf size, and in yield, shape, and time of coloring of fruit.
The tree types of these two nucellar-line strains were identified repeatedly among sister nucellar seedlings. Tree characters and fruit shape have indicated that at least one or two other genetic types probably were present among nucellar seedlings of the same seed-parent tree. That tree probably either included several genetic types, or produced genetic variations during formation of nucellar embryos.
One seedling type, probably of nucellar origin, which occurred only once among several hundred seedlings, differed conspicuously in tree and fruit.
A plot of old-line trees, budded directly from the seed parent of the nucellar seedlings, has been inferior to both nucellar-line plots in size of trees and leaves, in yield and time of coloring of fruit, and in percentage of soluble solids and solids/acid ratio of juice. The greater yield of the nucellar lines has been due mainly to their greater tree size. Earliness of fruit coloring has shown marked positive correlation with yield.
The better of the two nucellar lines of the plots (strain A) is recommended for trial in climatic conditions favorable to the Satsuma, especially in some navel orange districts.
Observation and tests have indicated absence of the psorosis and tristeza viruses from both seed-parent and nucellar lines.
Batchelor L. D., Cameron J. W. Nucellar seedling strains of citrus. Florida State Hort. Soc. Proc. 1949. 62:55-65.
Cameron J. W., Soost R. K. Size, yield, and fruit characters of orchard trees of citrus propagated from young nucellar-seedling lines and parental old lines. Amer. Soc. Hort. Sci. Proc. 1952. 60:255-64.
Frost H. B. Polyembryony, heterozygosis and chimeras in citrus. Hilgardia. 1926. 1(16):365-402. DOI: 10.3733/hilg.v01n16p365 [CrossRef]
Frost H. B. Nucellar embryony and juvenile characters in clonal varieties of citrus. Jour. Hered. 1938. 29:423-32.
Frost H. B. Characteristics in the nursery of citrus budlings of young nucellar-seedling lines and parental old lines. Amer. Soc. Hort. Sci. Proc. 1952. 60:247-54.
Hodgson R. W., Cameron S. H. Effects of reproduction by nucellar embryony on clonal characteristics in citrus. Jour. Hered. 1938. 29:417-19.
Olson E. O., Mcdonald J. R. Tristeza in Satsuma varieties in Texas. Plant Disease Reporter. 1954. 38:439-41.
“Student”. New tables for testing the significance of observations. “Student’s” Collected Papers. 1925. Cambridge, England: University Press. p. 115-20.
Swingle W. T. Recapitulation of seedling characters by nucellar buds developing in the embryo sac of Citrus. Sixth Internatl. Cong. Genet. Proc. 1932. 2:196-97.
Swingle W. T., Robinson T. R. The Silverhill: a promising and apparently hardy strain of Satsuma orange. Florida State Hort. Soc. Proc. 1931. 44:201-02.
Tanaka Tyozaburo. A monograph of the Satsuma orange, with special reference to the occurrence of new varieties through bud variation. Taihoku Imp. Univ., Faculty Sci. and Agr. Mem. 1932. 4:1-626. 53 pls.
Wallace J. M., Oberholzer P. C. J., Hofmeyer J. D. J. Distribution of viruses of tristeza and other diseases of citrus in propagative material. Plant Disease Reporter. 1956. 40:3-10.
Webber H. J., Batchelor L. D. The citrus industry, Vol. I. History, botany, and breeding, xx + 1028 p. 1943. Berkeley and Los Angeles: University of California Press. (In text reference to this volume, author and page precede editors and date.)
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