Amanda Box

Department of Plant Science

Waite Campus, University of Adelaide

Glen Osmond SA 5064

The major objective of the SA Hulless Barley Improvement Program is to develop hulless types for the following four end uses:

1. Low beta glucan feed types for monogastric animals

2. The malting and brewing industries

3. The food industry (e.g. low amylose)

4. Various industrial and commercial uses (e.g. low and high amylose)

In the first instance, hulless lines were derived from crosses made between covered cultivars/lines (Schooner, Skiff, Chebec, Galleon and WI 2646) and introduced hulless lines from CIMMYT, Mexico (CIMMYT 42002) and University of Saskatchewan, Canada (Richard, SB85216). During the latter stages of the program other hulless lines were derived from crosses made between introduced covered lines from various sources (UK, Europe, Northern Africa) and introduced hulless lines from western Canada (Western Canada Hulless Barley Co-op Trial) and CIMMYT (Hulless barley nurseries) and recycling a number of outstanding hulless lines from the program itself.

The hulless lines that are in the advanced stages of testing are showing a great deal of promise with respects to agronomic and malting quality performance. We have achieved hulless lines that yield equal to that of Schooner and up to 50% greater than hulless controls (Merlin, Morrell, Namoi and Richard). Many lines have improved straw strength and grain plumpness and are less susceptible to head loss.

Table I summarises the grain yield performance of WI 3107 and WI 3152 compared to Namoi and Schooner for the 1999 SARDI Stage 4 (Advanced trials grown at 22 locations around South Australia) trials. Grain yield has been expressed as a) the predicted mean (kg/ha) across all sites for 1999, b) percentage of Schooner (malting) and, c) percentage of Namoi (current Australian hulless cultivar).

Table I: Summary of the grain yield performances of WI 3107 and WI 3152 compared to Namoi and Schooner for the 1999 SARDI Stage 4 Trials.

A small to medium height plant with high malt extract, CCN and leaf rust resistance.

WI 3107 = (89/20)*78 is a line derived from the cross 89/20 = Galleon/CIMMYT 42002. CIMMYT 42002 is a hulless barley line from CIMMYT, Mexico and was selected for its bright, white and plump grain.

Scald – moderately susceptible at Turretfield Research Station 1996, 1997, 1998 and 1999

Powdery mildew – moderately susceptible at Callington 1998

Spot form of Net Blotch – moderately susceptible at Yeelanna 1995 and 1998 but resistant at Yeelanna in 1999

Cereal Cyst Nematode – resistant in tube test in 1995, 1996, 1997, 1998 and 1999

Leaf rust – moderately resistant at Weetulta 1997

Height – similar to Galleon but shorter than Schooner

Maturity – similar to Schooner and early Galleon

Head loss – excellent head retention

Straw strength – good straw strength

Early growth – erect

A semi-dwarf, high yielding hulless barley with CCN and scald resistance and moderate resistance to spot form of net blotch.

WI 3152 = (89/126)/J*11 is a line derived from the cross 89/126 = Skiff/CIMMYT 42002//Galleon. CIMMYT 42002 is a hulless barley line from CIMMYT, Mexico and was selected for its bright, white and plump grain.

Scald – resistant at Turretfield Research Station 1996, 1997, 1998 and 1999

Powdery mildew – moderately resistant at Callington 1998

Spot form of Net Blotch – moderately resistant at Yeelanna 1995 and 1998

Cereal Cyst Nematode – resistant in tube test in 1995, 1996, 1997, 1998 and 1999

Leaf rust – susceptible at Weetulta 1997

Height – semi-dwarf

Maturity – earlier than Skiff and similar to Schooner and Barque

Head loss – excellent head retention

Straw strength – short, stiff straw

Early growth – prostrate

Analysis of 1998 malted samples showed a wide range of variation in key malting traits, including very high malt extract levels obtained for the 'elite' hulless lines.

The Stage 3 and 2 trials grown at Brinkworth, Mid-North, South Australia and Weetulta, Yorke Peninsula, South Australia were used for micromalting and malting quality evaluation in 1998. The Hulless Collaborative trials grown at Condobolin and Wagga Wagga, New South Wales were used for micromalting and malting quality evaluation in 1998. There were 20, 64 and 55 lines evaluated from the Stage 3, Stage 2 and collaborative trials, respectively. For comparison, 4 covered controls (Barque, Galleon, Schooner and Skiff) and 3 hulless controls from Canada (Richard), NSW (Namoi), WA (Morrell) and North America (Merlin) were included in the Stage 3 trials. For comparison, 2 hulless controls from NSW (Namoi) and WA (Morrell) were included in the Stage 2 trials. In the collaborative trials, 3 hulless controls from NSW (Namoi), WA (Morrell) and North America (Merlin) were included.

Entries from Stage 3 trial were analysed for malt extract, DP, viscosity, wort beta glucan, malt and soluble proteins and friability. Entries from the Stage 2 and collaborative trials were analysed for malt extract, DP, viscosity and malt protein.

Overall, both the hulless controls and breeding lines consistently produced malt extracts 1 - 11 percentage points higher than Schooner. The greatest concern with malting hulless barley is achieving and maintaining maximum germination and even modification during the malting process. To measure this uniformity of grain modification, friabilities and Kolbach Index have been collected on hulless controls and breeding lines. As a result, we observed:

• Malt friabilities ranged between 61.8 – 92.5% (Stage 3 at Brinkworth) and 29.9 – 80.5% (Stage 3 at Weetulta)
• Friabilities were lower at Weetulta than Brinkworth
• Kolbach Index ranged between 25.68 – 39.73% for Stage 3 at Brinkworth
• Kolbach Index ranged between 23.58 – 32.60% for Stage 3 at Weetulta
• Variations between hulless breeding lines for high and low levels of viscosity and wort beta glucan do exist
• (Galleon x CIMMYT 42002)/58 produced the lowest levels for wort beta glucan and similar levels for viscosity compared to Schooner

Some hulless malt samples have shown low friability and Kolbach Index and increases in beta glucan and viscosity. These trends may be symptomatic of poor germination rather than inherently poor malting quality.

89/20*58 = (Galleon x CIMMYT 42002) performed exceptionally well with high levels of malt extract (86.21% Brinkworth) and moderately high levels of DP (476 Brinkworth). Viscosity and wort beta glucan levels were equal to that of Schooner but had lower levels of wort beta glucan than Schooner at Weetulta. This line also produced an excellent friability (90.2%) and Kolbach Index (39.73%) at Brinkworth.

89/20*78 = (Galleon x CIMMYT 42002) consistently produced moderately high malt extracts with viscosity levels 27% higher than Schooner and wort beta glucan levels 13% lower than Galleon. This line produced up to 12% higher friabilities than Barque and Galleon at Brinkworth. The Kolbach Index were variable with a high result (35.84%) obtained at Brinkworth and a low result (26.10%) obtained at Weetulta.

89/03*6045 = (Skiff x CIMMYT_42002) produced at both Weetulta and Brinkworth (Stage 2 results) very high malt extracts (86.01 and 87.77 respectively) and high levels of DP. More importantly, 89/03*6045 produced the lowest value for viscosity (1.65 cP) in all hulless barley trials analysed. Within these trials, there does exist a large variation for viscosity levels with the trend indicating that Galleon progeny is exhibiting higher levels of viscosity.

90/72*5008 = ((WI 2646 x CIMMYT 42002) x Chebec) produced moderately high malt extracts (85.99% Brinkworth) but low levels of DP (275 Brinkworth). This line produced viscosity and wort beta glucan levels 11% higher than Schooner and wort beta glucan levels up to 96% lower than Barque and Galleon. 90/72*5008 produced very good values for friability (90.20%) and Kolbach Index (36.39%) from Brinkworth.

SB94794 (zero amylose) developed by the University of Saskatchewan, Canada, Merlin developed by Western Plant Breeders, North America and three reselections from Sumire mochi derived populations were chosen to introgress the gene for waxy endosperm into both hulless and covered backgrounds. Merlin has a semi-dwarf plant type with a slightly later maturity than Skiff whereas SB94794 is taller than Schooner and has a similar maturity. Both lines have a hulless caryopsis and have very bright white kernels. Table II summarises the number of top and single crosses produced during 1999 using these waxy hulless parents. F₁ lines will be planted in January 2000 and F₂ populations will be screened for waxy progeny using the iodine staining method.

Table II: summarises the number of top and single crosses produced during 1999 using the seven waxy hulless parents