Prediction of the heterosis of Laminaria hybrids with the genetic distance between their parental gametophyte clones

Abstract

Eighteen microsatellite markers were used to determine the genetic distances between the parental gametophyte clones of 14 Laminaria hybrids, which were then used to establish a linear relationship with the heterosis (hybrid vigor) of economic traits including yield, mean blade try weight, mean blade fresh weight, blade length, blade width and mean blade thickness using regression analysis. Significant regression was found between the genetic distance (x) and the heterosis (y) of yield (y=115.10x−77.97, r=0.8151, p=0.00038), mean blade dry weight (y=115.23x −77.97, r= 0.8154, p=0.00038), mean blade fresh weight (y=100.08x− 57.85, r=0.7306, p=0.0030) and blade length (y=204.11x− 46.77, r= 0.6963, p= 0.00566). The prediction of the heterosis of Laminaria hybrids with the genetic distance between parental gametophyte clones will facilitate the selection of elite Laminaria hybrids by avoiding the timeconsuming and labor-intensive trait evaluation of a large number of hybridization combinations.

Towards domestication of giant kelp (Macrocystis pyrifera) in Chile: selection of haploid parent genotypes, outbreeding, and heterosis

“…The superiority of some of our inter-cultivar hybrids (Table 2, Figs. 2 and 3) compares well with crossing products of commercial L. japonica clones described by Li et al (2008). Furthermore, our observations include cases of hybrid depression and reciprocal asymmetry (Table 2; Fig.…”

“…Due to the dominant diploid state combined with obligatory sexual reproduction and dioecism, the occurrence of heterosis in kelps is not surprising, and a first case has been reported for Undaria by Hara and Akiyama (1985). Heterosis breeding strategies are presently applied in Laminaria mariculture in China, using intraspecific matings between Laminaria japonica cultivars (Li et al 2008) and reciprocal crosses between cultivars of L. japonica and L. longissima (Li et al 2007;Zhang et al 2007). …”

High genetic diversity in gametophyte clones of Undaria pinnatifida from Vladivostok, Dalian and Qingdao revealed using microsatellite analysis

“…Similar results were obtained in species of Saccharina. Li et al (2008b) found a significant relationship between the genetic distance of parental Laminaria (Saccharina) gametophyte clones measured using microsatellite markers and heterosis of agronomical traits of the first filial hybrids. All of these investigations have indicated that genetic distance between parental individuals, computed based on molecular markers such as microsatellites, AFLP and others, could be used to estimate the heterosis of their hybrids.…”

“…Precise prediction of the hybrid performance or heterosis before performing hybridization experiments enhances the efficiency of the breeding process. Such investigations have been conducted in the guppy, maize and Saccharina species (Shikano and Taniguchi, 2002;Kiula et al, 2008;Li et al, 2008b). Shikano and Taniguchi (2002) revealed that genetic distance measured by molecular markers positively correlated with the degree of heterosis in guppies (Poecilia reticulata).…”

Macrocystis mariculture in Chile: growth performance of heterosis genotype constructs under field conditions

“…More recently, closely related Laminaria species were crossed in order to produce superior genotypes in China Li et al 2007). Li et al (2008) used molecular techniques to correlate genetic distances between Lami naria parent lines and economically interesting characters of their heterosis products. Our results show that Macro cystis will now be a new candidate, offering the potential of heterosis breeding in another economically interesting kelp species.…”