In controlled tests, 110 cultivars (77.5%) of common bean (Phaseolus vulgaris L.) responded to broad bean wilt virus (BBWV) with a localized infection (resistant), while 32 cultivars (22.5%) reacted with local and systemic infection (susceptible). The majority of susceptible cultivars were of the yellow-podded (wax bean) and red kidney types. In F1, F2, and backcross populations of the BBWV-resistant cultivar Sanilac with the BBWV-susceptible ‘California Light Red Kidney’ (‘CLRK’) resistance to systemic infection was conferred by a single dominant gene, to which the symbol Bbw is assigned. BBWV was not transmitted in 471 ‘CLRK’ seeds derived from severely infected plants.
To determine the genealogy of cultivated lettuce in the United States, a survey was conducted on the pedigree of proprietary and publicly developed lettuce cultivars registered from 1970 through 2004. This was facilitated through information furnished by the U.S. Plant Variety Protection Act, U.S. patent, and journal publication of registered cultivars. In total, there were 328 registered cultivars of which 90.5% (297 cultivars) were from proprietary and 9.5% (31) from public breeding programs. The lettuce cultivars of this era are 61.6% crisphead, 19.5% loose leaf, 13.7% cos/romaine, 4.9% butterhead, and 0.3% latin lettuce types. To facilitate an understanding of current U.S. lettuce germplasm, the most recombined and putatively elite cultivars in the development of new cultivars were identified. The 10 most recombined cultivars were ‘Salinas’ (parent of 28 new cultivars), ‘Calmar’ (27), ‘Vanguard’ (22), ‘Vanguard 75’ (13), ‘Vanmax’ (13), ‘Prize Head’ (12), ‘Parris Island Cos’ (12), ‘Empire’ (11), ‘Great Lakes 659’ (11), and ‘Red Coach 74’ (10). The types of breeding populations used for new cultivar development during this era were two-parent (52% of new cultivars), within cultivar selection (31%), three-parent (7%), backcross two or greater (5%), backcross one (2%), four or more parents (2%), and interspecific cross (1%).
A 3rd recessive, male-sterile gene in muskmelon (Cucumis melo L.) is named male sterile-3 and symbolized ms-3. Male sterile-3 is phenotypically distinct from male-sterile genes ms-1 or ms-2.
Inheritance of an indehiscent anther (ia) mutant in the common bean (Phaseolus vulgaris L.) was studied. Dehiscence was incompletely dominant in heterozygotes making classification difficult in backcross and F2 populations. Progeny tests were necessary to determine that the character was conditioned by a single recessive gene. The symbol ia is proposed to denote the indehiscent anther gene.
Inheritance of growth habit was studied in F1, F2, and backcross progenies of peach [Prunus persica (L.) Batsch ‘Com-Pact Redhaven’]. Segregation ratios indicate that compact growth habit is conditioned by a single dominant allele, for which ‘Compact Redhaven’ is heterozygous. The symbol Ct is proposed for this locus.
Six phosphoglucomutase phenotypes were observed in pecan [Carya illinoensis (Wangenh.) K. Koch] progeny after controlled pollinations. At least one locus (Pgm-1) is present that controls polymorphism of phosphoglucomutase (PGM) isozymes in pecan. The inheritance appears simple with three observed alleles. However, progeny produced from two crosses resulted in significant deviation from the expected segregation ratios. Out of 65 named cultivars, 61 were of a single phenotype, and two of six possible phenotypes were not observed. Only one region of PGM activity was consistently expressed by gel electrophoresis from pecan tissue.
More than 30 pecan [Carya illinoensis (Wangenh.) K. Koch] seedlings of `Riverside' have exhibited an unusual leaf morphology described as lace-leafed. Seedlings have relatively low vigor, compound leaves, and leaflets with deeply serrated margins with higher length: width ratios than normal seedings. Some leaves are both pinnate and palmately compound and some leaflets are lobed. The segregation ratio of lace-leafed seedlings for one gene controlling a polymorphic genetic marker supports the hypothesis that lace-leafed seedlings result from selfing of `Riverside.' Nine percent (three of 33) of seedlings derived from selfing of `Riverside' exhibited the lace-leafed morphology, suggesting a recessive trait controlled by one or two genes. The gene(s) controlling this phenotype in pecan is arbitrarily designated the ll gene(s).
The usefulness of isozyme banding patterns as genetic markers in kiwifruit [Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson] was investigated using starch gel electrophoresis. Fifty-four entries putatively belonging to seven female and two male kiwifruit cultivars were examined for 13 enzyme systems (AAT, ACO, GDH, G6PDH, IDH, MDH, ME, MNR, NDH, 6PGD, PGI, PGM, and SKDH). Four enzyme systems, ACO, MDH, NDH, and SKDH, showed identical banding patterns in all clones surveyed. Of the remaining enzymes, AAT, PGI, and PGM had the best discriminating power. Six enzyme systems (GDH, G6PDH, IDH, ME, MNR, and 6PGD), though showing polymorphic banding patterns, were poorly resolved. All the New Zealand cultivars were uniquely identified by the simultaneous comparison of the AAT, PGI, and PGM zymograms. Some enzyme systems were also polymorphic among plants within the same cultivar, thus proving the heterogeneity of kiwifruit material introduced into Europe in the early 1970s.