Class 9 Mutants

Member lines: bm-8, bm-15, bm-18

Gross epicuticular wax phenotype: Bloomless

Epicuticular wax morphology:

(see Jenks et al., 1992 and scanning electron micrograph to the right of this table)

tissue	cork-silica cell associated wax	cuticle wax
leaf sheath (abaxial surface)	globs	sparse plates
leaf blade (abaxial surface)	small globs	smooth

Linkage group: bm4 (all members of this class are allelic)

Genotype: bm9bm9HH

Epicuticular wax load:

(data from Agronomy Farm trial 1992)

line	abaxial leaf sheath	leaf blade
bm-8	1.36 +/- 0.14	2.11 +/- 0.25
bm-15	1.06 +/- 0.25	1.45 +/- 0.10
bm-18	1.08 +/- 0.13	1.32 +/- 0.09

These lines have an average of 42% more wax on their leaf blades than their wildtype parents.

Leaf sheath epicuticular wax chemistry:

Leaf sheath epicuticular wax free fatty acids

FFA homologue	% total FFAs	load (mg/cm2)
C16	7.15	0.48
C18	6.68	0.45
C20	0.64	0.04
C22	23.7	1.60
C24	23.9	1.61
C26	21.3	1.44
C28	15.0	1.01
C30	1.50	0.10
C32	0.09	0.01
total	100	6.75

Class 9 mutant sheath wax contains 58% free fatty acids. They have an increased amount of the C22-C26 FFA homologues over their wildtype counterparts. The TLC at right shows that these mutants have almost no fatty aldehydes and contain more esters than the wildtype.

Agronomic characters:

line	yield without drought (kg/ha)	yield in drought (kg/ha)
bm-15	4667	1209
bm-18	2898	888

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