Registration of ‘GA09436-16LE12’: A new soft red winter wheat cultivar adapted to the US southeast region

Abstract

Soft red winter wheat (Triticum aestivum L.; SRWW) is a major crop in the US southeast (SE) region. However, growing successful wheat crop is challenged by many stresses resulting in substantial losses in yield and quality. To alleviate these challenges, developing new cultivars with high yield potential with resistance to major pests in the region and good quality is warranted. This constitutes the major goal of the SRWW breeding programs ate the University of Georgia (UGA) and the regional institutions including the southern universities GRAINS (SUNGRAINS) programs. ‘GA09436-16LE12’ (Reg. no. CV-1209, PI 700011) SRWW cultivar was among the adapted wheat developed and released by the UGA College of Agricultural and Environmental Sciences in 2019. While GA09436-16LE12 is generally adapted to the US SE region, it specifically well fit to the Georgia environments. It has high yield, very good resistance to most dominant diseases including leaf (caused by Puccinia triticina Erikss.) and stripe (caused by P. striiformis Westend.) rusts; powdery mildew (caused by Erisyphe graminis); and Soil-borne wheat mosaic virus. GA09436-16LE12 has improved Fusarium head blight (caused by Fusarium graminearum Schwabe) which is reflected in lower levels of Deoxynivalenol toxin and Fusarium damaged kernels levels. It also showed moderate field resistance to Hessian fly [Mayetiola destructor (Say)] although it is susceptible to the biotypes B, C, O, and L. GA09436-16LE12 has good grain volume weight and good milling and baking quality as a SRWW.

Abbreviations

SBWMV

Soil-borne wheat mosaic virus

DON

deoxynivalenol

EYT

elite yield trial

FHB

Fusarium head blight

GSGPT

Georgia's Small Grain Performance Trials

PYT

preliminary yield trial

SE

southeast

SRC

solvent retention capacity

SRWW

soft red winter wheat

SUNGRAINS

Southeastern University GRAINS

SUNPRE

SUNGRAINS preliminary collaborative trial

SUNWHEAT

SUNGRAINS wheat collaborative trial

UGA

University of Georgia

USW

Uniform Regional Wheat

1 INTRODUCTION

Soft red winter wheat (Triticum aestivum L.; SRWW) is a major crop in Georgia and the US southeast (SE) region. However, its production is constantly threatened by several challenges including biotic stresses. Therefore, developing new adapted cultivars is essential to enhance and sustain wheat production in the US SE region. The wheat growers and industry in the SE region are ready to adopt new cultivars that will allow them to be competitive on national and international markets. Our goal at the University of Georgia (UGA) Small Grains breeding program in collaboration with the regional Southeastern University GRAINS (SUNGRAINS) programs (which includes The University of Georgia, University of Arkansas, University of Florida, Louisiana State University Agricultural Center, Clemson University, Texas A&M University, and North Carolina State University) is to develop new SRWW cultivars adapted to the US SE region. These cultivars should also meet the wheat growers and industry production and quality attributes. ‘GA09436-16LE12’ (Reg. no. CV-1209, PI 700011) was developed by the UGA small grains breeding program with the collaboration of the SUNGRAINS breeding programs and released by the UGA College of Agricultural and Environmental Sciences in 2019. GA09436-16LE12 is medium late maturing and high yielding cultivar with good resistance to major foliar diseases, including leaf (caused by Puccinia triticina Erikss.) and stripe (caused by P. striiformis Westend) rusts, and powdery mildew (caused by Erisyphe graminis). It is also resistant to Soil-borne wheat mosaic virus (SBWMV) and Hessian fly [Mayetiola destructor (Say)] under field conditions. However, it is moderately susceptible to Fusarium head blight (caused by Fusarium graminearum Schwabe; FHB) and Hessian fly biotypes B, CO, and L under greenhouse conditions. GA09436-16LE12 has very good flour yield, grain volume weight, and good cookie baking qualities.

2 METHODS

2.1 Early generation development

GA09436-16LE12 is derived from the cross of ‘USG 3120’/GA 011124-8LE28 made in 2009 in the UGA Griffin campus, Griffin, GA. The USG 3120 is a SRWW cultivar released by UGA (GA991209-6E33) in 2009 and licensed to the UniSouth Genetics Company for its commercialization in the US SE region. It was used in the GA09436-16LE12 cross because of its earliness, high yield potential, and good leaf and stripe resistance, but it is susceptible to SBWMV. The second parent of GA09436-16LE12, GA011124-8LE28, has SBWMV resistance in addition to its good adaptation to Georgia and the SE region. The F₁ plants were grown in in the greenhouse in 2010 and selected individual spikes were selected from F₂ to F₅ generations grown at Plains, GA, from 2011 to 2014, respectively. About 200 spikes were selected in F₂ and subsequently 10 spikes were selected at F₃, F₄, and F₅. Individual spikes were selected based on their agronomic phenotype, reaction to diseases (leaf and stripe rusts in particular), Hessian fly, and viruses (mainly SBWMV). Selected spikes were grown as head-rows at next each generation. Selection was made among rows and spikes within selected rows. GA09436-16LE12 originated from a selected F₅ row in 2015. The selected row was harvested in bulk and included in the preliminary yield trials (PYT) in the following crop cycle (2016).

2.2 Line selection and evaluation

GA09436-16LE12 was initially tested in the PYTs planted at Plains and Griffin, GA, UGA Research Experiment Stations in 2015. Based on GA09436-16LE12 good performance in PYT, it was advanced and evaluated in the Georgia elite yield trials (EYT) grown in three locations across Georgia (Plains, Griffin, and Calhoun), and one location each in Alabama and Mississippi (Table 1). GA09436-16LE12 was subsequently evaluated for 3 years (2017–2019) in the Georgia Small Grain Performance Trials (GSGPT). GA09436-16LE12 was tested in the SUNGRAINS regional nursery (SUNPRE) at four locations in Georgia and the neighboring states (North Carolina, Louisiana, and Arkansas) in 2016. In 2017 it was tested in the advanced regional SUNGRAINS nursery (SUNWHEAT) at locations in Georgia, North Carolina, Louisiana, Arkansas, and Florida. Subsequently in 2017, it was evaluated in the regional Uniform Southern Wheat (USW) Nursery grown in 21 locations across the US SE.

TABLE 1. Average of grain yield, grain volume weight, heading date, plant height, and reactions to leaf rust, stripe rust, and Fusarium head blight (FHB) of GA09436-16LE12 and commonly grown soft red winter wheat cultivars included in Georgia elite yield trials at Plains, Calhoun, and Griffin, GA, and in Alabama and Mississippi in 2016.

Entry	Grain yield	Grain vol. weight	Days to heading	Plant height	Leaf rust	Stripe rust	Powdery mildew	FHB Severity
	kg ha^−1	kg m^−3	Julian days	cm	0–9^a	0–9^a	0–9^a	0–9^a
GA09436-16LE12	5581.8	776.1	94.0	101.6	0.0	0.0	0.5	4.0
AGS 2024	5548.1	778.6	93.3	86.4	0.0	0.0	0.0	5.0
SH 5550	5501.1	791.5	94.2	94.0	1.0	0.0	0.5	6.5
Savoy	6321.5	778.6	88.5	83.8	0.0	0.0	1.5	5.5
Hillard	5400.2	769.6	104.1	101.6	0.5	0.5	1.5	2.0
Disease highest rating^b	–	–	–	–	6.5	8.0	2.7	1.5
LSD 0.05	271.5	15.1	4.5	6.5	1.0	1.5	1.5	2.5
No. of environments	5	5	5	5	4	4	1	2

• ^a Leaf and stripe rusts, powdery mildew, and FHB ratings are as follows: 0 = resistant, 9 = very susceptible.
• ^b Indicate the highest disease score of the most susceptible genotype in the trial.

GA09436-16LE12 was first evaluated in the PYT in 2015 and subsequently tested in the EYT grown across Georgia, Alabama, and Mississippi (Table 1) and in the regional 2016 SUNGRAINS preliminary regional nursery (SUNPRE) conducted in Georgia, North Carolina, Louisiana, and Arkansas. During the 3 years (2017–2019), GA09436-16LE12 was tested in the Georgia's Small Grain Performance Trials (GSGPT), conducted by the UGA Statewide Testing program across Georgia (Table 2). It was also tested the second year in the advanced SUNGRAINS (SUNWHEAT) nursery in 2017 (Table 3) and in the USW in 2018 (Table 4) across 21 locations in the SE region.

Core Ideas

• GA09436-16LE12 is a new soft red winter wheat cultivar well adapted to Georgia and high yielding in the US southeast.
• GA09436-16LE12 is resistant to rusts, powdery mildew, Hessian fly, and Soil-borne mosaic virus, and medium resistant to Fusarium head blight.
• GA09436-16LE12 has good flour yield and cookie diameter.

TABLE 2. Average of grain yield and volume weight, days to heading, plant height, and reactions to diseases (leaf and stripe rusts) of GA09436-16LE12 and commonly grown soft red winter wheat cultivars included in Georgia's Small Grain Performance Trials from 2017 to 2019.

Entry	Grain yield statewide	Grain vol. weight	Days to heading	Plant height	Leaf rust	Stripe rust
	kg ha^−1	kg m^−3	Julian days	cm	0–9^a	0–9^a
GA09436-16LE12	5918.0	800.5	95.1	101.6	0.0	1.0
AGS 2024	6368.6	756.8	96.3	94.0	0.5	2.3
AGS 3030	5797.0	755.5	94.5	88.9	2.2	0.3
AGS 3040	6106.3	742.6	98.3	96.5	0.4	2.0
Disease highest rating^b	–	–	–	–	9.0	9.0
LSD 0.05	277.1	13.0	3.9	5.8	1.5	1.0
No. of environments	14	14	14	14	10	11

• ^a Leaf and stripe rusts ratings are as follows: 0 = resistant, 9 = very susceptible.
• ^b Indicate the highest disease score of the most susceptible genotype in the trial.

TABLE 3. Average of grain yield and volume weight, heading date, plant height, and reactions to powdery mildew, leaf, stripe rusts, and Fusarium head blight (FHB) of GA09436-16LE12 and commonly grown soft red winter wheat cultivars included in regional Multi-State SUNGRAINS in 2017.

Entry	Grain yield	Grain vol. weight	Days to heading	Plant height	Powdery mildew	Leaf rust	Stripe rust	FHB severity
	kg ha^−1	kg m^−3	Julian days	cm	0–9^a	0–9^a	0–9^a	0–9^b
GA09436-16LE12	4418.3	763.2	89.7	86.4	0.0	0.0	0.0	4.0
AGS 3000	3416.3	718.1	83.7	83.8	2.0	3.3	0.0	–
SS8641	4223.3	723.3	90.3	83.8	0.5	0.0	0.5	7.0
Hilliard	4384.7	682.1	93.9	86.4	1.0	0.0	0.2	1.5
Savoy	4606.6	749.0	83.2	83.8	2.0	0.3	2.3	5.4
Disease highest rating^b	–	–	–	–	3.5	9.0	9.0	9.0
LSD 0.05	233.3	15.5	3.5	4.5	1.0	2.1	1.5	3.4
No. of environments	6	6	6	6		6	6	6

• ^a Powdery mildew, leaf and stripe rusts, and FHB ratings are as follows: 0 = resistant, 9 = very susceptible.
• ^b Indicate the highest disease score of the most susceptible genotype in the trial.

TABLE 4. Average of grain yield and volume weight, days to heading, plant height, lodging, and reactions to leaf and stripe rusts and powdery mildew of GA09436-16LE12 and commonly grown soft red winter wheat cultivars included in the Uniform Southern Wheat nursery planted in Georgia and other locations in the Southeast region in 2018.

Entry	Grain yield	Grain vol. weight	Days to heading	Plant height	Leaf rust	Stripe rust	FHB severity	FHB DON	Powdery mildew	Soil borne mosaic virus
	kg ha^−1	kg m^−3	Julian	cm	0–9^a	0–9^a	0–9^a	ppm	0–9^a	0–9^a
GA09436-16LE12	5178.3	773.5	109.7	101.6	0.0	1.1	2.0	9.2	4.1	3.1
AGS 2000	4895.8	733.6	106.8	99.1	1.2	6.8	3.8	14.5	5.8	8.0
Jamestown	4828.6	743.9	103.4	91.4	1.4	2.7	2.6	7.3	2.5	3.2
Hilliard	5756.6	734.9	108.6	99.1	1.7	2.6	1.9	9.9	1.2	2.3
PIO 26R41	5568.3	722.0	109.3	91.4	3.8	2.8	2.9	16.6	2.2	1.1
Disease highest rating^b	–	–	–	–	5.8	8.3	5.9	22.8	7.8	8.5
LSD 0.05	377.5	17.7	7.1	6.7	1.5	2.0	1.7	10.7	1.2	2.2
No. of environments	22	22	22	22	11	13	7	7	6	5

• ^a Leaf and stripe rusts, FHB severity, and powdery mildew ratings are as follows: 0 = resistant, 9 = very susceptible.
• ^b Indicate the highest disease score of the most susceptible genotype in the trial.

The PYTs are un-replicated trials while the EYT, GSGPT, SUNPRE, SUNWHEAT, and USW were arranged in a randomized complete block design (RCBD) with two to four replicates. The plot consists of seven, 3-m-long rows, 15 cm apart for each entry and was the same in all yield trials. While the EYT were grown in five locations (three sites in Georgia and one location each in Alabama and Mississippi), the PYT were grown in two locations in Georgia only. Similarly, the GSGPT trials were grown in multiple sites across Georgia, and the SUNGRAINS and USW trials were conducted across the SE region.

Agronomic and quality and reaction to the major pests predominant in the region of GA09436-16LE12 and commonly grown checks in Georgia and the SE region were collected in yield trials reported in Tables 1–6. Leaf and stripe rusts reactions were collected in all yield trials (Tables 1–4) while Powdery mildew and FHB data were collected in all yield trials except GSPT (Tables 1, 3, and 4). SBWMSV data were collected only in the USW (Table 4). Similarly, Hessian fly data were recorded under field conditions at Plains, Griffin, and Tifton between 2017 and 2019, while the reaction to biotypes B, C, O, and L under greenhouse conditions was scored in 2019 (Table 5). A scale of 0–9 (0 = immune and 9 = susceptible) was used to score disease severity of leaf and stripe rusts, powdery mildew (Gill et al., 1985), FHB (Jones, 2000), and SBWMV (Perovic et al., 2009). However, FHB vomitoxin deoxynivalenol (DON) levels in the seed sample were expressed in ppm. It is important to note that FHB disease severity data collected in the yield trials reflects mainly the FHB type II resistance (Rudd et al., 2001), an indication of the FHB disease spread across spikelets in infected spikes. The evaluation of Hessian fly reaction was expressed as a percentage of susceptible plants scored. This was done by assessing the insect larva per 20 plants sampled randomly (Gill et al., 1985).

TABLE 5. Reactions of GA09436-16LE12 and commonly grown soft red winter wheat cultivars to Hessian fly under field conditions at Griffin, Plains, and Tifton, GA, USA in 2017–2018, as well as their reaction to major Hessian fly biotypes under greenhouse and artificial inoculation conditions in 2018.

Entry	Hessian fly severity^a
	Locations			Biotypes^b
	Plains	Griffin	Tifton	B	C	O	L
	%
GA09436-16LE12	0	25	10	100	100	100	100
AGS 2024	5	35	5	–	–	–	–
AGS 3030	0	0	0	–	–	–	–
AGS 3040	15	0	0	–	–	–	–
AGS 2000	–	–	–	100	100	100	100
Jamestown	–	–	–	5	0	100	100
Hilliard	0	60	75	0	0	100	100
PIO 26R41	0	0	10	0	0	0	0
Pest highest rating^c	85	60	90	100	100	100	100
LSD 0.05	9	8	7	6	7	8	6
No. of environments	3	2	1	2	2	2	2

• ^a Hessian fly severity = % of infested plants by the fly.
• ^b Hessian fly severity under inoculated and greenhouse conditions.
• ^c Indicates the highest disease score of the most susceptible genotype in the trial.

TABLE 6. Means of flour yield, softness equivalent, flour protein, and cookie diameter of GA09436-16LE12 and commonly grown soft red winter wheat cultivars grown in the Uniform Regional Wheat nurseries during 2018.

Entry	Flour yield^a	Softness equivalence^a	Flour protein^a^b	Sodium carbonate SRC^a	Cookie diameter^a
	g kg^−1	%	g kg^−1	%	cm
GA09436-16LE12	705.0	55.6	80.1	68.5	18.6
AGS 2000	706.0	55.5	77.3	69.3	18.9
Jamestown	671.4	52.3	75.0	72.8	18.3
Hilliard	678.0	59.5	70.1	70.4	18.6
PIO 26R41	697.7	58.1	67.4	69.0	18.6
LSD 0.05	15.3	2.5	5.0	1.5	0.5
No. of environments	22	22	22	22	22

• Abbreviation: SRC, solvent retention capacity.
• ^a Evaluations done by the USDA-ARS Wheat Quality Laboratory, Wooster, OH.
• ^b Flour protein at 14% grain moisture.

Quality data were collected using seed samples from the USW grown over 21 locations in the US SE region. Seed samples are sent to the USDA-ARS wheat quality laboratory in Wooster, OH, where milling and baking quality data is generated. Milling evaluations are conducted on wheat grain samples tempered to 15% moisture and milled using a modified Brabender Quadrumat Senior milling system (C.W. Brabender Instruments Inc.) following the procedures described by Finney and Andrews (1986). Flour yield is defined as the percentage total flour weight of the tempered grain weight. Softness equivalence is the percentage break flour of the total flour weight while flour protein content is determined using a near infrared analyzer (SpectraStar, Unity Scientific) according to Approved Method 39-11.01 (AACC, 2024). Main baking attributes (cookie diameter and solvent retention capacity [SRC]) are measured according to Approved method 10-52.02. (AACC, 2024) where SRC is a physical test performed on hard and soft wheat flours to determine their end use, baking quality, and hydration response during dough mixing. The SRC is a measure of the water absorption and retention profile of gluten proteins, damaged starch, and pentosans. Four different types of solvents—water, sucrose, sodium carbonate and lactic acid—are used to determine the SRC. It allows the possibility to describe the flour's ability to absorb water during the mixing process and its ability to release that water during the baking process. It also analyzes the level of starch damage in flours and establishes a flour quality profile for predicting functionality and specification conformance.

To conduct DNA marker analyses that allow to test for presence of known genes and/or quantitative trait loci in regional germplasm, leaf samples from seedlings of GA09436-16LE12 and checks were collected and sent to the USDA-ARS Eastern Small Grains Genotyping Lab at Raleigh, NC, which conduct these analysis (https://www.ars.usda.gov/southeast-area/raleigh-nc/plant-science-research/docs/small-grains-genotyping-laboratory/regional-nursery-marker-reports/uniform-eastern-southern-soft-red-winter-wheat-nurseries/).

2.3 Seed purification and increase

The first seed production of GA09436-16LE12 was produced from an F₇ small plot (10 m²) planted in Plains in 2016 in EYT that was rogued thoroughly for aberrant types. Small three drill strips of 50 m² and six large drill strips of 150 m² of GA09436-16LE12 were planted in Plains in 2017 and 2018, respectively. GA09436-16LE12 seed was maintained pure by visual rogueing off-type (taller, different spike color, absence of awns) plants. In 2019, the Georgia Seed Development Commission produced breeder seed of GA09436-16LE12 on about 2 ha at Plains.

2.4 Statistical analysis

The analysis of variance (ANOVA) within years and across locations using SAS 6.0.3 (SAS Institute, 1999) was performed to analyze data of GA09436-16LE12 performance. Data analyzed included grain yield and grain volume weight from breeding and Georgia and regional yield trials. A combined analysis across location-years was performed when single location error variances were homogeneous. In this case, only entries common to the trials across years were included in the ANOVA. PROC MIXED procedure was used to estimate genotypic adjusted means within location and year–location combinations. Comparisons of traits means between genotypes were performed by using protected LSD (P = 0.10) test, where genotype × environment mean square was used to estimate the standard error of differences between genotype means across environments.

3 CHARACTERISTICS

3.1 Agronomic and botanical description

Plant height of GA09436-16LE12 varied with environment between 86.4 cm in the SUNWHEAT trials (Table 3) to 101.6 cm in GSGPT and USW trials (Tables 2 and 4). In the EYT, GA09436-16LE12 plant height was 101.6 cm, similar to ‘Hilliard’ (Griffey et al., 2020) (101.6 cm) but taller that the other checks which varied between 83.8 cm ‘Savoy’ (Johnson et al., 2018) and 94.0 cm (‘SH 5550’; Meherrin Agricultural and Chemical Co.) (Table 1). However, while GSGPT GA09436-16LE12 had similar plant height (101.6 cm), it was not significantly different from AGS 3040 (96.5 cm) in the GSGPT trials, but it was taller AGS 3030 (88.9 cm) and ‘AGS 2024’ (94.0 cm) (Table 2). Plant height of GA09436-16LE12 in the SUNWHAET trials (86.4 cm) was not significantly different from all other checks (Table 3). Similar height of GA09436-16LE12 (101.6 cm) was also registered in the USW trials. This was similar to plant height to ‘AGS 2000’ (Johnson et al., 2002) and Hilliard (99.1 cm), but taller than ‘Jamestown’ (Griffey et al., 2010) and PIO 26R41 (91.4 cm) (Table 4).

GA09436-16LE12 is in general a medium early cultivar. In the EYT, it headed 94.0 days after planting which was similar to AGS 2024 (93.3 days) and SH 5550 (94.2 days) but significantly different from checks Savoy (88.3 days) and Hillard (104.1 days) (Table 1). Similar heading date (95.1 days) was registered for GA09436-16LE12 in the GSGPT (Table 2) but was not significantly different from heading dates for all checks including AGS 2024 (96.3 days), AGS 3030 (94.5 days), and AGS 3040 (98.3 cm). GA09436-16LE12 headed 89.7 days after planting in the SUNWHEAT trials (Table 3), whereas checks headed between 83.2 days for Savoy to 93.3 days for Hilliard. In the regional USW trials (Table 4), GA09436-16LE12 heading date (109.7 days) was comparable to checks varying between 103.4 days for Jamestown and 109.3 days for PIO26R41.

GA09436-16LE12 possesses a semi erect plant growth habit at juvenile stage with blue plant color and is erect and not twisted with waxy flag leaves at the boot stage. At boot stage, it has a blue–green plant color, and flag leaves are erect and twisted. The spikes are white, awned, semi-dense, inclined, and oblong/strap shape. The glumes are white, non-pubescent, long, and medium narrow. The shoulders are rounded and medium; the beaks are acute with medium width. GA09436-16LE12 has red, soft textured, ovate with a non-collared medium brush seed. The cheek is rounded with a medium width and depth crease, and midsize germ.

GA09436-16LE12 was observed during several generations including seed increase (2017–2018 and breeder seed in 2019) and showed to be uniform and stable. Hence, it is expected that GA09436-16LE12 to remain stable intact during its reproduction for its essential and distinctive characteristics. However, under some specific environmental conditions, GA09436-16LE12 can present some variants. These include taller plants (more than 30 cm) at a frequency of less than 1 in 1,000 plants and awnless plants at the same frequency. These variances, however, are within the commercial acceptable limits for all described traits.

3.2 Pests reactions

Among wheat diseases, leaf diseases, including leaf and stripe rusts, are considered a major threat to wheat production in Georgia and the US SE region (Ghimire et al., 2020). Other pests, including FHB disease, Hessian fly, and SBWMV are a huge problem for wheat in the SE region. Hence, developing SRWW cultivars with resistances to these pests is essential to enhance wheat productivity in the region. GA09436-16LE12 combines excellent resistance to leaf and stripe rusts with scores of 0 and 0–1.1 for both diseases respectively (Tables 1–4). Checks however, except for stripe rust for AGS 2000 (Table 4), were resistant or moderately resistant with scores of 0–3.8 and 0–2.8 for leaf and strip rusts, respectively. Both diseases were severe which was reflected by the highest scores for most susceptible genotypes in the trials that varied from 5.8–9 and 8–9 for leaf and stripe rust, respectively. GA09436-16LE12 showed medium resistance to powdery mildew with scores varying from 0 (Tables 1 and 3) in the EYT and SUNWHEAT to 4.1 (Table 4) in the SUNWHEAT and the USW trials. The highest scores recorded for the most susceptible genotypes included in these trials were 2.7 in the EYT (Table 2) and 7.8 in the USW (Table 4). The reaction of GA09436-16LE12 to SBWMV tested in the USW (Table 4) is moderate resistant (score of 3.1) compared to the checks reaction that varied from 1.1 (PIO 26R41) to 8.0 (AGS 2000). The highest score registered for the most susceptible entry was 8.5, indicating a high infestation by the virus. Based on DNA marker analysis using Kompetitive Allele Specific polymerase chain reaction (KASP) (Helguera et al., 2003; Liu et al., 2014) showed that GA09436-16LE12 possesses important resistance genes for major prevalent pests including the sbm1, Yr17/Lr37/Sr38, and Pm54 genes that provides resistance indicated above for SBWMV; stripe, leaf, and stem rusts; and powdery mildew, respectively. A moderate reaction to FHB was demonstrated by GA09436-16LE12 in different tests. On a 0–9 scale, GA09436-16LE12 had scores varying from 2.0 registered in the USW yield trials (Table 4) to 4.0 registered in the EYT (Table 1) and SUNGRAINS (Table 3). Check scores for FHB ranged from 2.0 for the late moderately resistant check Hilliard to 6.5 (SH 5550) in the EYT (Table 1); 1.5 (Hilliard) to 7.0 (SS8641) in the SUNGRAINS (Table 3); and 1.9 (Hilliard) to 3.8 (AGS 2000) in the USW trials (Table 4). The highest scores for FHB registered for most susceptible genotypes in the trials were 7.5, 9.0, and 5.9 in the EYT, SUNGRAINS, and the USW trials, respectively. This shows clearly that FHB disease was prevalent in most environments where the trials were conducted. In recent years and scabby years, FHB caused significant yield and quality losses due to scabby kernels and high DON vomitoxin accumulation in kernels (Ghimire et al., 2020). GA09436-16LE12 DON levels scored in the USW trials (Table 4) were 9.2 ppm compared to 9.9 ppm of the resistant check Hillard and 16.6 ppm of PIO 26R41. The highest DON level scored among the USW entries was 22.8 ppm.

A few insects, including Hessian fly, are also a major threat to wheat production in the US SE region causing significant yield losses for wheat growers and the wheat industry (Buntin & Cunfer, 2000). The reaction of GA09436-16LE12 to this insect was conducted under field conditions in 2015–2016 at three locations in Georgia (Plains, Griffin, and Tifton) (Table 5). It was also tested under greenhouse in Griffin in 2016 for its reaction to the four most prevalent biotypes (B, C, O, and L) of Hessian fly in Georgia and the SE region (Table 5). GA09436-16LE12 had good resistance levels to Hessian fly under all three locations. Its severity scores ranged from 0 to 25%. The checks meanwhile had scores ranging 0% for AGS 3030, 5%–35% for AGS 2024, 0%–75% for Hilliard, and 0%–10% for PIO 26R41. The reaction of GA09436-16LE12 to the specific biotypes B, C, O, and L was susceptible and similar to AGS 2000, whereas PIO 26R41 was resistant to all biotypes and Jamestown and Hilliard were resistant to B and C and susceptible to A and L biotypes (Table 5).

3.3 Grain yield performance and quality parameters

GA09436-16LE12 performed well for grain yield across years and locations (Tables 1–4). Results from EYT grown across five locations (three in Georgia and one in each of Alabama and Mississippi) in 2016, showed that GA09436-16LE12 yielded 5581.8 kg ha⁻¹, similar to most checks including AGS 2024 (5548.1 kg ha⁻¹), SH 5550 (5501.1 kg ha⁻¹), and Hillard (5400.2 kg ha⁻¹), however, it was less that the yield of Savoy (6321.5 ha⁻¹) (Table 1). Similarly, the grain volume weight of GA09436-16LE12 (776.1 kg m⁻³) was comparable to checks except SH 5550 (791.5 kg m⁻³) (Table 1).

In GSGPT yield trials grown across 14 location-years in Georgia from 2017 to 2019, GA09436-16LE12 yield an average 5918.0 kg ha⁻¹, which was less than the yield of the check AGS 2024 (6368.6 kg ha⁻¹) but similar to that of AGS 3030 (5797.0 kg ha⁻¹) and AGS 3040 (6106.3 kg ha⁻¹) (Table 2). In the same trials, the grain volume weight of GA09436-16LE12 (800.5 kg m⁻³) was superior to all checks including AGS 2024 (756.8 kg m⁻³), AGS 3030 (755.5 kg m⁻³), and AGS 3040 (742.6 kg m⁻³) (Table 2).

In the SUNGRAINS regional trials SUNWHEAT grown over six locations across the SE states (Arkansas, Georgia, Louisiana, Texas, South Carolina, and North Carolina) in 2017, the grain yield and volume weights of GA09436-16LE12 were 4418.3 kg ha⁻¹ and 763.2 kg m⁻³, respectively (Table 3). The GA09436-16LE12 grain yield was higher than AGS 3000 (3416.3 kg ha⁻¹), but not significantly different from SS8641, Hilliard, and Savoy (4223.3, 4384.7, and 4606.6 kg ha⁻¹, respectively) (Table 3). Similarly, except for Savoy which had similar grain weight volume (749.0 kg m⁻³) to GA09436-16LE12 (763.2 kg m⁻³), all other checks had comparable grain weight volume (varying from 682.1 to 723.3 kg m⁻³ registered for Hilliard and SS8641, respectively) than GA09436-16LE12.

Data from the USW trials grown across 22 locations across the US SE region in 2018 (Table 4) show that GA09436-16LE12 grain yield (5178.3 kg ha⁻¹) was equivalent to AGS 2000 (4895.8 kg ha⁻¹) and Jamestown (4828.6 kg ha⁻¹) but lower than Hilliard (5756.6 kg ha⁻¹) and PIO26R41 (5568.3 kg ha⁻¹) (Table 4). The grain volume weight of GA09436-16LE12 (773.5 kg m⁻³) in the same trials was higher than all checks including AGS 2000 (720 kg m⁻³), Jamestown (743.9 kg m⁻³), Hilliard (734.9 kg m⁻³), and PIO26R41 (722.0 kg m⁻³) (Table 4).

The main grain quality parameters of GA09436-16LE12 compared to SRWW commonly grown cultivar checks under Georgia and the US SE region conditions are reported in Table 6. These include the flour yield and softness, two main traits that characterize SRWW wheat market class. These traits were evaluated on seed samples collected from the regional USW nurseries. GA09436-16LE12 showed very good flour yield (705.0 g kg⁻¹) similar to AGS 2000 (706.0 g kg⁻¹) and PIO26R41 (697.7 g kg⁻¹), but significantly higher than Jamestown (671.4 g kg⁻¹) and Hilliard (678.0 g kg⁻¹). The softness equivalence, a specific character of the soft wheat classes, of GA09436-16LE12 grain (55.6%) was not significantly different from checks, which varied from 52.3% of Jamestown to 59.5 of Hilliard (Table 6).

The flour protein, SRC, and cookie diameter are also significant quality traits that determine the end-use product of the SRWW. GA09436-16LE12 flour protein (80.1 g kg⁻¹) was similar to AGS 2000 (77.3 g kg⁻¹) and Jamestown (75.0 g kg⁻¹). However, GA09436-16LE12 flour protein was significantly higher than PIO26R41 (67.4 g kg⁻¹) and Hilliard (70.1 g kg⁻¹). SRC of GA09436-16LE12 (68.5%) was similar to AGS 2000 (69.3%) and PIO 26R41 (69.0%) but lower than Jamestown (72.8%) and Hilliard (70.3%). Cookie diameter produced from GA051207-14E53 dough (18.6 cm) was excellent, superior to Jamestown (18.3 cm), less than AGS 2000 (18.9 cm), but not significantly different from Hillard and PIO 26R41 (18.6 cm) which varied from 18.3 cm (Jamestown) to 18.9 cm (AGS 2000) (Table 6).

4 AVAILABILITY

GA09436-16LE12 breeder seed is produced and maintained by the Georgia Seed Development Commission, at 2420 S. Milledge Ave. Athens, GA 30605. The production and distribution rights of all classes of certified seed of GA09436-16LE12 were transferred from UGA to the UGA-Research Foundation (UGARF), 150 B Coverdell Center, 500 D. W. Brooks Dr. Athens, GA. A seed sample was deposited in the USDA-ARS National Center for Genetic Resources Preservation where it is available for distribution 20 years after publication. Request for small seed quantities of GA09436-16LE12 for research purposes can be obtained directly from the corresponding author, and this seed distribution will be done according to the provisions of the Wheat Worker's Code of Ethics (National Wheat Improvement Committee, 1995).

AUTHOR CONTRIBUTIONS

Mohamed Mergoum: Conceptualization; data curation; formal analysis; funding acquisition; investigation; methodology; project administration; resources; software; supervision; validation; visualization; writing—original draft; writing—review and editing. Jerry W. Johnson: Conceptualization; data curation; funding acquisition; investigation; methodology; resources; software. Steve Sutton: Investigation; methodology; validation. Benjamin Lopez: Data curation; investigation; validation. Daniel Bland: Investigation. James W. Buck: Investigation; methodology; validation. G. D. Buntin: Investigation; methodology; validation. Daniel J. Mailhot: Investigation; methodology; validation. Stephen A. Harrison: Data curation; formal analysis; investigation; validation. J. Paul Murphy: Data curation; investigation; methodology; validation. Richard E. Mason: Data curation; investigation; methodology; validation. Russell L. Sutton: Data curation; investigation; methodology; validation. Md A. Babar: Data curation; investigation; methodology; validation. Amir M. H. Ibrahim: Data curation; investigation; methodology; validation. Richard Boyles: Data curation; investigation; validation. Gina L. Brown-Guedira: Data curation; formal analysis; methodology; validation. Byung-Kee Baik: Data curation; investigation; validation. Z. Chen: Investigation. David Marshall: Data curation; validation. Sue E. Cambron: Investigation; methodology; validation. X. Chen: Investigation; methodology; validation. Christina Cowger: Data curation; investigation; methodology; validation.

ACKNOWLEDGMENT

A sincere thanks to the SUNGRAINS breeding program's technical staff that contributed to the evaluation of the GA09436-16LE12. The authors also would like to thank all the colleagues at the UGA Research Experiment Stations in Plains, Griffin, Calhoun, Tifton, and Midville; the colleagues at the Georgia State-Wide Testing; and the Plant Pathology and Entomology Departments.

CONFLICT OF INTEREST STATEMENT

The authors report no conflicts of interest.