Improving efficiency of breeding for higher crop yield

Abstract

Exclusive selection for yield raises, the harvest index of self-pollinated crops with little or no gain in total bipmass. In addition to selection for yield, it is suggested that efficient breeding for higher yield requires simultaneous selection for yield's three major, genetically controlled physiological components. The following are needed: (1) a superior rate of biomass accumulation. (2) a superior rate of actual yield accumulation in order to acquire a high harvest index, and (3) a time to harvest maturity that is neither shorter nor longer than the duration of the growing season. That duration is provided by the environment, which is the fourth major determinant of yield. Simultaneous selection is required because genetically established interconnections among the three major physiological components cause: (a) a correlation between the harvest index and days to maturity that is usually negative; (b) a correlation between the harvest index and total biomass that is often negative, and (c) a correlation between biomass and days to maturity that is usually positive. All three physiological components and the correlations among them can be quantified by yield system analysis (YSA) of yield trials. An additive main effects and multiplicative interaction (AMMI) statistical analysis can separate and quantify the genotype × environment interaction (G × E) effect on yield and on each physiological component that is caused by each genotype and by the different environment of each yield trial. The use of yield trials to select parents which have the highest rates of accumulation of both biomass and yield, in addition to selecting for the G × E that is specifically adapted to the site can accelerate advance toward the highest potential yield at each geographical site. Higher yield for many sites will raise average regional yield. Higher yield for multiple regions and continents will raise average yield on a world-wide basis. Genetic and physiological bases for lack of indirect selection for biomass from exclusive selection for yield are explained.

Nutrient uptakes and their contributions to yield in peanut genotypes with different levels of terminal drought resistance

“…Wallace et al (1993) suggested that indirect selection for yield is most effective when applied to traits that already integrate most of the genetic and environmental effects that lead to yield. More rapid progress may be achieved by using physiological and morphological traits (Nigam et al, 2005).…”

QTL Mapping for Reproductive Maturity in Lowland Switchgrass Populations

“…However, improvements in photosynthetic efficiency have been limited (Evans 1993), many annual crop breeders have selected for an optimal duration of growth as the avenue to increasing biomass yield (Wallace et al 1993). For switchgrass, Esbroeck et al (1998) proposed that an extended duration of vegetative growth in switchgrass by selecting for delayed flowering might be a means to achieve higher biomass yield.…”

The adaptation, agronomical and quality characteristcs of some dry bean (Phaseolus vulgaris L.) cultivars and lines under Erzurum ecological conditions

“…Bazı nohut çeşitlerinin Orta Anadolu koşullarına adaptasyonunu araştıran Bıçaksız ve Kayan (2011), yaptıkları korelasyon ve path analizlerinde tane verimine en önemli doğrudan etkiyi biyolojik veriminin yaptığını ve ayrıca, diğer ögelerin de tane verimine biyolojik verim üzerinden dolaylı etkide bulunduğunu belirlemişlerdir. Wallace et al (1993), fasulyede tane verimini belirleyen en önemli üç unsurun biyolojik verim, hasat indeksi ve vejetasyon süresi olduğunu bildirmişler ve fasulyede verim yönünden yapılacak seleksiyonlarda bu üç özellik arasındaki ilişkiyi bilmenin önemli olduğuna vurgu yapmışlardır.…”