Genetic Progress in Soybean of the U.S. Midsouth

Abstract

Yield increase in crops has occurred due to plant breeding and improved production and management techniques. The amount of increase due to plant breeding in soybean in the southern USA has not been determined. The objective of this study was to evaluate the genetic improvements in soybean yield and other important agronomic traits. ‘CNS’ and ‘S‐100’ were chosen as representative ancestral lines from the 1940s. ‘Ogden’ and ‘Lee’, ‘Hill’ and ‘Essex’, and ‘TN 5‐85’, and ‘Hutcheson’ were released in early 1950s, late 1950s and early 1970s, and late 1980s, respectively. The experiments were conducted in Knoxville Experiment Station in Knoxville, TN and at the Ames Plantation near Grand Junction, TN, for 3 yr, and at the Milan Experiment Station in Milan, TN, and at the Highland Rim Station in Springfield, TN, for 2 yr. Results showed that cultivar improvement increased soybean yield 14 kg ha−1 per year. Yield increase over time was linear. This linear increase demonstrates that a yield plateau in the U.S. Midsouth has not been reached in soybean [Glycine max (L.) Merr.]. Most of the increase has come via genetically related elite by elite parent crosses. However, infusion of exotic germplasm into elite germplasm can often promote increases in yield, as in the development of Hutcheson. Current cultivars showed better yield stability and more response to favorable growing conditions than ancestral lines. Genetic improvement resulted in shorter plant height and decreased lodging. Oil content was increased until the 1980s, but then started to decrease. However, because of correlated effects, protein content started to increase after the 1980s.

Assessment of Genetic Improvement in Grain Yield Potential and Related Traits of Kabuli Type Chickpea (Cicer arietinum L.) Varieties in Ethiopia (1974-2009)

“…Progress made in genetic yield potential and associated traits produced by different crops improvement program and the benefits obtained have been evaluated and documented in different countries concluded that genetic improvement in those crops have produced modern cultivars with improved yield potential [11][12][13][14][15][16][17]. This is also true for some crops in Ethiopia [18][19][20][21][22][23][24].…”

Breeding Progress for Grain Yield and Yield Related Characters of Kabuli Chickpea (Cicer arietinum L.) in Ethiopia Using Regression Analysis

“…Furthermore, progress in chickpea breeding in the country has also been constrained by lack of good early maturing variety with ability to resist known chickpea diseases. Understanding the amount of genetic gain realized through past crop breeding efforts is absolutely essential to improving the efficiency and effectiveness of future breeding endeavors (Evans, 1993;Ustun et al, 2001;Waddington et al, 1987). Besides quantifying the progress obtained in a certain period, the genetic gain analysis also enables aggregation of other information, such as comparison of the gains obtained with the use of different breeding strategies or in different environments (Specht & Williams, 1984).…”

“…Among the available procedures, the performance of genotypes in common environments regressed over years of varietal release of a given crop as a continuous quantitative variable provided the most direct estimate of genetic gain from breeding and has widely been used in different crops (Cox et al, 1988). For example, genetic progresses using the same procedure were reported in barley (Martintello et al, 1987), groundnut (Mozingo et al, 1987), sunflower (Pereira et al, 1999), wheat (Brancourt-Hulmel et al, 2003;Parveen & Khalil, 2011;Rodrigues et al, 2007;Shearman et al, 2005), soybean (Jin et al, 2010;Liu et al, 2012;Morrison et al, 2000;Ustun et al, 2001) and maize (Luque et al, 2006). Genetic progress made over time from breeding of different crops in Ethiopia have also been studied using the same procedure and documented in haricot bean (Bezawuletaw et al, 2006), maize (Worku & Zelleke, 2007), barley (Fekadu et al, 2011), groundnut (Hagos et al, 2012) and faba bean (Tolessa et al, 2015).…”

Soybean Architecture Plants: From Solar Radiation Interception to Crop Protection

“…Nevertheless, the authors also observed that the daily biomass gain was higher in newer cultivars and suggested that this better performance was associated with a higher content of chlorophyll and the drainage capacity in reproductive organs. Ustun et al [65] verified that the masses of the cultivars between 1940 and 1970 were considerably small, demonstrating that there was increase in drainage capacity of reserve for the reproductive organs in the cultivars.…”