Genetic Diversity of Fish in Aquaculture and of Common Carp (Cyprinus carpio) in Traditional Rice–Fish Coculture

Abstract

The genetic diversity of cultured species (e.g., plants and fish) has decreased as intensive agriculture and aquaculture have increased in recent decades. Maintaining genetic diversity in agriculture is a significant concern. To test whether aquaculture affects the genetic diversity of aquatic animals and whether traditional agriculture could help maintain genetic diversity, we conducted a meta-analysis to quantify the genetic diversity of cultured and wild populations. We also examined the genetic diversity and population genetic structure of common carp (Cyprinus carpio) in the traditional rice–fish coculture in the south of Zhejiang Province, China, using 20 microsatellite loci. The results of the meta-analysis showed a negative overall effect size of all cultured aquatic animals that were tested both when weighted by population replicate and when weighted by the inverse of variance. Aquaculture has caused a general decline in the genetic diversity of many cultured aquatic animals. The results from the survey of a traditional rice–fish coculture system in the south of Zhejiang Province of China showed high levels of genetic diversity in all 10 sampled populations (mean Na = 7.40, mean Ne = 4.57, mean I = 1.61, mean He = 0.71, and mean Ho = 0.73). Both the conventional analysis and a model-based analysis revealed a high and significant genetic divergence among the 10 sampled populations all over the three counties (FST value ranged from 0.00 to 0.13, and Nei’s genetic distance ranged from 0.07 to 0.62). Populations within Yongjia and Jingning counties were also genetically differentiated, respectively. Furthermore, molecular variance (AMOVA), membership coefficients estimated by STRUCTURE, PCoA, and migration network analysis supported the findings from pairwise FST values. Our results suggest that the traditional rice–fish coculture plays an important role in maintaining the genetic diversity of carp cocultured in rice paddies and future policies should favor the conservation of the rice–fish system and raise the awareness of farmers on methods to maintain carp genetic diversity.

Timing of Fungal Insecticide Application to Avoid Solar Ultraviolet Irradiation Enhances Field Control of Rice Planthoppers

“…High-profit agriculture has been emerging in Southern China, expanding from traditional rice-fish coculture systems [23,24] to rice-shrimp, rice-crab, rice-soft shell turtle and rice-bullfrog coculture or rotation systems [25][26][27]. To prevent the high-profit aquacultures from contamination with chemical residues, insecticidal compounds are prohibited for field control of major rice pests, such as RPH and leaf folder pests that cause damage in the coculture and rotation systems.…”

Microsatellite marker Based Genetic Monitoring of Exotic Common Carp Strains (Cyprinus carpio L. and Cyprinus carpio communis) in the Chenab River, Punjab, Pakistan

“…According to a previous study conducted by (39), an analysis of genetic structure revealed that the carp populations co-cultivated in paddies located in the southern region of Zhejiang Province were predominantly in uenced by germplasm exchange resulting from breeding introductions. In their study, (40) reported that based on the estimation of delta K values, the inferred genetic clusters of either 2 or 4 exhibited high probabilities.…”

“…The study employed the two-phased model (TPM) in conjunction with a 90% single step mutation rate, 1000 replications, and the mode shift test proposed by Ye et al (2022) to evaluate potential recent bottlenecks in populations of common carp and mirror carp strains (Table 6). The presence of a pronounced disparity between observed heterozygosity and anticipated heterozygosity in certain populations of common carp strains suggests the potential occurrence of a bottleneck event within those populations.…”

Sustainable Agriculture: Theories, Methods, Practices and Policies

“…Taking Limpopo Province as an example, Tlou E. Mogale et al [12] evaluated the productivity of different species of sorghum intercropping at different cowpea densities, and proposed that the combination of intercropping and no-tillage can improve crop yield and productivity, thereby promoting agricultural sustainability. Taking the rice-fish coculture system in Jingning, Qingtian, and Yongjia counties of Zhejiang Province as an example, Ye et al [13] compared and evaluated the effects of various aquaculture and rice-fish coculture systems on the genetic diversity of aquatic animals, and proposed that the implementation of the rice-fish coculture system can improve the genetic diversity and food security of aquatic species, thereby promoting agricultural sustainability.…”