AMES, IOWA
Iowa State University

A gene conditioning high oleic maize oil, olc1
--Allen Wright

Maize (Zea mays L.) oil with higher levels of oleic acid relative to linoleic acid would have greater stability. Thus high oleic acid oil is a desirable breeding objective. From EMS-treated B73 (paraffin oil pollen treatment) a mutation has been recovered that increases oleic acid concentration of the seed oil. This mutation (designated Olc1 ) has a partially dominant effect . The oleic acid concentrations of non-mutant B73, heterozygous Olc1 and homozygous Olc1 were approximately 27, 35 and 52%, respectively (Table 1). B-A translocations (Table 2) indicate that the Olc1 gene is located on the long arm of chromosome 1.

Table 1. Chi square analysis of olc1/Olc1 F2 and olc1/Olc1 x olc1/olc1 segregations
 
olc1/Olc1 F2 Obs. Exp.
Phenotype (x) (m) (x-m2)/m
Low oleic: olc1/olc1
(Range: 24.8 - 30.1% oleic)
27 25 0.16
 Intermediate oleic:olc1/Olc1
(Range: 32.4 - 38.1% oleic)
52 50 0.08
 High oleic: Olc1/Olc1
(Range: 50.3 - 55.2% oleic)
21 25 0.64
     Chi square=0.88 P=64.54% 
olc1/Olc1olc1/olc1 Obs. Exp.
Phenotype (x) (m) (x-m2)/m
Low oleic: olc1/olc1
(Range: 25.5 - 30.1%)
36 35 0.0286
 Intermediate oleic: Olc1/olc1
(Range: 33.0 - 38.1%)
34 35 0.0286
    Chi square=0.0572 P=81.27%

Table 2. Maximum oleic acid content of B-A translocation crosses to mutant (Olc1) and non-mutant B73 (maximum value of at least 10 individual kernel determinations).
 
 
oleic composition (%)
B-A Stock
Olc1
Control
TB-1Sb 
35.4
42.1
TB-1La
41.5
51.9
TB-2Sb
29.5
35.5
TB-2Lc
31.8
35.6
TB-3Sb
30.3
34.7
TB-3La
31.8
29.7
TB-4Sa
36.8
42.3
TB-4Lf
39.0
39.7
TB-5Sc
30.9
40.4
TB-5La
30.5
40.9
TB-6Sa
33.4
38.2
TB-6Lc
32.3
36.9
TB-7Sc
36.4
43.3
TB-7Lb
35.3
39.3
TB-8Lc
30.1
33.9
TB-9Sd
31.4
34.1
TB-9Lc
34.2
39.2
TB-10Sc
33.4
37.6
TB-10L20
30.0
35.5


Please Note: Notes submitted to the Maize Genetics Cooperation Newsletter may be cited only with consent of the authors

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