Interspecific hybridization between Crassostrea angulata and C. ariakensis

Abstract

Interspecific hybridization can generate heterosis, which is proven to be a useful tool in selective breeding programs for oyster culture. Crassostrea angulata and C. ariakensis are two important economic shellfish species in China. We conducted 2 × 2 reciprocal crosses to determine whether these two species can cross-fertilize and their hybrids can hatch, survive and perform heterosis. Fertilization was found symmetrical without delay. The rate of fertilization success of C. angulata ♀ × C. ariakensis ♂ was lower than that of C. ariakensis ♀ × C. angulata ♂, and the success rate of both hybridizations was lower than that of two intraspecific crosses each. During the planktonic period, survival rate of the progeny was lower in the hybrid crosses than in the intraspecific crosses. On day 360, mean shell height of the progeny of C. angulata ♀ × C. angulata ♂ was highest, which was followed by that of C. angulata ♀ × C. ariakensis ♂, C. ariakensis ♀ × C. ariakensis ♂ and C. ariakensis ♀ × C. angulata ♂ in a descending order. Morphology of adults produced by the hybrid crosses was similar to that of C. angulata. Both hybrids underwent normal gonad development and produced mature gametes in the mating season. This study provided new insights into the quantitative traits in interspecific crosses of Crassostrea species, thus being of guidance value for selective breeding of oyster.

Molecular and Fitness Data Reveal Local Adaptation of Southern and Northern Estuarine Oysters (Crassostrea ariakensis)

“…Whether they should be considered two subspecies requires genomic variations in future studies to classify their taxonomic status by comparing the sequence variation between intra-and inter-specific oysters (Wang et al, 2010). The lower survival and growth rates of larvae bred from reciprocal hybrid crosses between the northern and southern populations than in those from intrapopulation crosses indicate that there is no intraspecific heterosis, which is concordant with interspecific reciprocal crosses between high-salt habit C. gigas and low-salt habit C. ariakensis in that their hybrids had lower fitness (Yao et al, 2015). For species distributed along similar environmental (salinity) gradients, however, significant interspecific heterosis was detected between C. ariakensis and C. hongkongensis (Qin et al, 2020).…”

Growth performance and biochemical composition of the oysters Crassostrea sikamea , Crassostrea angulata and their hybrids in southern China

“…Similarly naturally occurring fertile hybrid between C. gigas and C. sikamea has also been observed (Camara et al., ). Previous reports (Yao et al., ; Zhang et al., ) indicate that hybrids in the Crassostrea genus were completely fertile, with the exception C. hongkongensis and C. gigas crosses (Zhang et al., ). These findings suggest that genomic introgression between different oyster species is possible.…”

“…In fact, many interspecific hybrid oysters are known to exhibited hybrid inferiority. Hybrid progeny usually showed slow growth than progeny of maternal parent (Xu et al., ; Yao et al., ; Zhang et al., ). On the other hand, although the interspecific hybrid spat between C. ariakensis × C. hongkongensis showed growth heterosis, the survival of hybrid larvae were significantly lower than the oysters of the intraspecific crosses (Huo et al., ).…”

Does New Urbanization Support the Rural Inclusive Green Development under Domestic Circulation in China?

“…By the end of the 13th Five-Year Plan period, the number of cities in China had reached 684, and the total built-up area had reached 60,300 square kilometers, which indicates that China's housing and urban-rural construction has made great achievements. However, the Chinese government should be more vigilant about the disorderly development that occurs during the rapid development of urbanization, especially the blind expansion of the edges of large and medium-sized cities, which has led to the degradation of soil and water resources and the destruction of the ecological environment [52]. At the level of social urbanization, the upward trend in the proportion of pensioners in the total population is a manifestation of the results of improving the pension insurance system and raising the level of pension security, and it is also an important aspect of promoting social urbanization and thus promoting rural development.…”