Factors Affecting Isoflavone Content in Soybean Seeds Grown in Thailand

Table 1

Varietal characteristics of 14 certified varieties* of soybean used in the experiments [14, 15].

(a)

Variety	Chiangmai 2	Chiangmai 5	Chiangmai 60	Chakkrabhandhu 1	KKU 35	Nakhon Sawan 1	SJ 1
Certified year	1998	2006	1987	1998	1994	1986	1965
Days to 50% flowering	31–35 d	33–35 d	32–34 d	43 d	37 d	26–32 d	35-36 d
Days to harvest	77 d	85–100 d	89–92 d	111 d	104 d	75–80 d	85–95 d
Maturity group	Early	Moderate	Moderate	Late	Late	Early	Moderate
100 seeds weight	25 g	13–15 g	16–20 g	11 g	16 g	16–20 g	11–15 g
Protein/oil content	39.8%/20.2%	33.4%/20.1%	39.1%/22.9%	41.3%/22.2%	46.6%/20.1%	36.7%/9.1%	40.2%/16.6%
Disease resistance	Downy mildew	Rust	Rust, bacterial pustule, and downy mildew	Downy mildew and antracnose	Bacterial pustule	Bacterial pustule and soybean mosaic virus	None
Disease susceptibility	Rust	None	None	Rust	Downy mildew and rust	Downy mildew, rust, and antracnose	Rust
Seed yield	1,463 kg/ha	2,419 kg/ha	1,750–2,188 kg/ha	1,800 kg/ha	1,913 kg/ha	1,538 kg/ha	1,562.5–1,875 kg/ha
Recommended; planting location	All regions	All regions	All regions	All regions	Lower northern, central, and northeastern regions	Lower northern and upper central regions	Northern, central, and northeastern regions
Recommended; planting season	All seasons	All seasons	All seasons	Early rainy and dry seasons	All seasons	Rainy season	Rainy season

∗Certified by Department of Agriculture, Ministry of Agriculture, Thailand.

(b)

Variety	SJ 2	SJ 4	SJ 5	Srisamrong 1	Sukhothai 1	Sukhothai 2	Sukhothai 3
Certified year	1965	1976	1980	2007	1986	1995	1999
Days to 50% flowering	36 d	34-35 d	33–35 d	26–28 d	30–35 d	29 d	39-40 d
Days to harvest	92–97 d	89–98 d	88–96 d	72–77 d	83–88 d	82–88 d	90–93 d
Maturity group	Moderate	Moderate	Moderate	Early	Moderate	Moderate	Moderate
100 seeds weight	11–15 g	15–18 g	13–16 g	13–15 g	9–12 g	13–15 g	11–13 g
Protein/oil content	38.8%/21.3%	39.0%/20.5%	41.9%/19.3%	35.9%/14.5%	36.4/23.2%	37.4%/9.0%	39.5%/12.2%
Disease resistance	Bacterial pustule	Rust and antracnose	Rust, soybean mosaic virus, antracnose, and purple seed stain	Downy mildew	Bacterial pustule and soybean mosaic virus	Bacterial pustule, downy mildew, and soybean mosaic virus	Antracnose and downy mildew (moderate)
Disease susceptibility	Rust and downy mildew	Bacterial pustule	Bacterial pustule	None	Purple seed stain and rust	Rust	Bacterial pustule
Seed yield	1,250–1,875 kg/ha	1,875 kg/ha	2,000 kg/ha	1,819 kg/ha	1,538 kg/ha	1,813–1,938 kg/ha	1,863 kg/ha
Recommended; planting location	All regions	Northern and central regions	All regions	Lower northern region	Upper central region	Lower northern and central regions	All regions
Recommended; planting season	Late rainy and dry seasons	All seasons	Widely adapted variety	N/A 055 68 1384	All seasons but not suitable for middle and late rainy seasons in upper northern region	All seasons but not suitable for middle, and late rainy seasons in upper northern region	All regions

∗Certified by Department of Agriculture, Ministry of Agriculture, Thailand.