Genomic imprinted genes in reciprocal hybrid endosperm of Brassica napus

Background Genomic imprinting results in the expression of parent-of-origin-specific alleles in the offspring. Brassica napus is an oil crop with research values in polyploidization. Identification of imprinted genes in B. napus will enrich the knowledge of genomic imprinting in dicotyledon plants. Results In this study, we performed reciprocal crosses between B. napus L. cultivars Yangyou 6 (Y6) and Zhongshuang 11 (ZS11) to collect endosperm at 20 and 25 days after pollination (DAP) for RNA-seq. In total, we identified 297 imprinted genes, including 283 maternal expressed genes (MEGs) and 14 paternal expressed genes (PEGs) according to the SNPs between Y6 and ZS11. Only 36 genes (35 MEGs and 1 PEG) were continuously imprinted in 20 and 25 DAP endosperm. We found 15, 2, 5, 3, 10, and 25 imprinted genes in this study were also imprinted in Arabidopsis, rice, castor bean, maize, B. rapa, and other B. napus lines, respectively. Only 26 imprinted genes were specifically expressed in endosperm, while other genes were also expressed in root, stem, leaf and flower bud of B. napus. A total of 109 imprinted genes were clustered on rapeseed chromosomes. We found the LTR/Copia transposable elements (TEs) were most enriched in both upstream and downstream of the imprinted genes, and the TEs enriched around imprinted genes were more than non-imprinted genes. Moreover, the expression of 5 AGLs and 6 pectin-related genes in hybrid endosperm were significantly changed comparing with that in parent endosperm. Conclusion This research provided a comprehensive identification of imprinted genes in B. napus, and enriched the gene imprinting in dicotyledon plants, which would be useful in further researches on how gene imprinting regulates seed development.

DEVELOPMENT OF SINGLE CROSS HYBRIDS FROM Momordica charantia BY FULL DIALLEL CROSSES

A field experiment was carried out in the plastic houses , College of Agricultural Engineering Ssciences , University of Baghdad during the spring season 2018. Six inbred lines of bitter gourd were entered into full diallel crosses, and planted during 2018-2019 season (six inbred lines symbolized as 1,2,3,4,5,6 +15 diallel hybrid + 15 reciprocal hybrid + control hybrid) according to randomized complete block design (RCBD) with three replicates, each experimental unit occupied 6 plants. Results revealed a significant differences among the genotypes in most of studied traits, The reciprocal hybrid 5×4 gave the highest values in leaf chlorophyll content (27.61 mlg mg-1), sex ratio (0.611), fruit setting percent (85.74%), and plant yield (2.005 kg), while the diallel hybrid 1×4 gave the highest values in leaves area (1.172 m2), sex ratio (0.747), fruits number (23.16), and plant yield (2.023 kg plant-1), Also the hybrid 6×4 gave the highest value in plant yield (2.105 kg plant-1), and the hybrid 1×3 gave the highest value in total phenols concentration (5.67 mlg gm-1), and the hybrid 2×3 gave the highest value in fruits weight (105.58 gm), charantin concentration (0.616 gm). Furthermore, many of reversal and reciprocal hybrids showed a positive hybrid abundance in the desired direction among the studied parameters, The reciprocal hybrid 6×4 gave the highest hybrid abundance in fruit weight (59.17%) and plant yield (120.3%), also the hybrid 5×4 gave the highest hybrid abundance in plant yield (69.99%).

The degree of dominance and heterosic effect in tomato hybrids on the main economic features

In Dagestan, like many southern subjects of the country, the environment of vegetable crops tomato is the most common crop. The basis for getting high tomato yields are heterosic hybrids. The research work was carried out during 2018-2019. on the experimental field of the Federal Agricultural Research Center of the Republic of Dagestan. The object of the study in 2018 were hybrids of tomato of the first generation of recyproccal interbreeding. In 2019, direct and reverse artificial crossings involved 11 pairs of initial forms of early-ripe and medium-ripened groups with higher productivity. Reciprocal hybrids with the participation of the variety Local in pair L 23/12, L 17/03, 23/04 and Spartacus on the grounds of "the number of fruit branches and the number of fruits" was high and, although the parents had the same indicators on these grounds (the number of fruit-bearing branches in the variety Local - 4.2 pieces, L 23/12 - 4.2 pieces, L 23/04 - 4.4 pieces and Spartacus - 4.0). In reverse combinations, heterosis was manifested, but the effect was lower compared to the indicators in direct combinations. The reciprocal hybrids of the pair of Varieties Spartacus and Local had a high heterosic effect in the reverse combination, when The Local acted as a maternal form (the degree of heterosis by the number of fruit-bearing branches 121% instead of 17% and the number of fruits on the first brush 124% instead of 22% in the direct combination of Spartacus x Local).Four reciprocal hybrid combinations with positive overdominance have been revealed. The degree of dominance in the "number of fruits on the first brush" ranged from - 0.4 to 104. The results of the study of the dominance and heterosis effect of the "number of fruits on the plant" indicate the high sectional value of the reciprocal hybrids studied.

Physiological status for fingerlings of kaluga and reciprocal hybrid sterlet x kaluga in the wintering period

Wintering is one of the most complicated biotechnical processes in pisciculture, and its success depends on a wide spectrum of biotic and abiotic factors, first of all on the fish physiological status before this period. Sturgeon fishes are believed to stop feeding under the water temperature below 4 °C that causes essential reorganization of their metabolism because of transition to endogenous feeding. Physiological status of fingerlings of kaluga and reciprocal hybrid sterlet x kaluga is compared in the beginning, middle and end of wintering, with comparative characteristic of their peripheral blood reaction and understanding of starvation influence on their digestive and hemopoietic systems. The fingerlings of both species were kept in cages of warm-water farm and fed with fodder. The fingerlings of kaluga started the wintering with improper physiological status, with evident pathological processes expressed as eosinophilia, macrocytic hyperchromic anaemia, increase of immature erythrocytes, and pathomorphological changes of erythrocytes (poikilocytosis, anisocytosis, karyorhexis, hemolysis). These symptoms could be caused by either herpesvirus infection or cumulative polytoxicosis, but results of hematological and histological analysis in the middle and end of the wintering confirmed the viral nature. Thus, mass disease and mortality of fish is possible in conditions of the temperature increase in spring. Therefore, prophylactic measures are recommended for overwintered kaluga fingerlings to enhance their immune and physiological status, such as addition of vitamins C and E, probiotics and prebiotics to fodder. On the contrary, the fingerlings of reciprocal hybrid sterlet x kaluga had a high physiological status before and during wintering, in spite of a rather high portion of eosinophiles in their leukogram.

Production value, chemical composition and colour of fillets of the reciprocal hybrid of Siberian sturgeon with green sturgeon (Acipenser baeri Br × (Acipenser baeri × Acipenser medirostrisAyres)

Fillet yield, colour, chemical composition and fatty acid composition in the reciprocal hybrid (SSZ) of Siberian sturgeon with its crossbred with green sturgeon were analysed. It was found that fillet yield in relation to the weight of gutted and deheaded carcass did not deviate from the parent forms. SSZ does not keep the salmon-pink colour of tissue, which is typical of the father form. Its tissue contains more (P ≤ 0.01) protein and less (P ≤ 0.01) water than the parental tissue as well as less (P ≤ 0.01) fat than the father’s tissue. The percentage of MUFA in tissue lipids corresponds to their proportion in the father form, whereas the corresponding values for SFA and PUFA are closer to the father form and much higher (P≤ 0.01) than in the mother form. A 100 g portion of the SSZ tissue for consumption contains a higher total amount of n-3 acids as well as EPA and DHA than the parent fish, with a higher difference in comparison with Siberian sturgeon.    

Compatibility of Schistosoma haematobium, S. intercalatum and their hybrids with Bulinus truncatus and B. forskalii

Schistosoma haematobium and S. intercalatum readily hybridize with each other producing generations of viable hybrid offspring. Experiments were designed to investigate the infectivity and viability of the S. haematobium×S. intercalatum F1 and F2 hybrid larvae in their two intermediate snail hosts compared with the parental species. Analysis of the data obtained suggested that the S. haematobium [male ]×S. intercalatum [female] F1 hybrid miracidia were more infective to Bulinus truncatus than to B. forskalii, and also more infective to B. truncatus compared with the parental S. haematobium miracidia. This hybrid was also observed to have a greater cercarial productivity from both intermediate hosts and these cercariae were shown to be more infectious and to have a longer longevity compared with the cercariae of S. haematobium, S. intercalatum and the S. haematobium [female]×S. intercalatum [male ] F1 hybrid cercariae. The S. haematobium [female]×S. intercalatum [male ] F1 hybrid was shown not to be very successful in all stages of the investigations. The results indicate that the S. haematobium [male ]×S. intercalatum [female] F1 hybrid may have many reproductive advantages over the reciprocal hybrid and the parental schistosome species. The significance of the results is discussed in relation to the epidemiological consequences occurring in Loum, Cameroon, and other areas where S. haematobium and S. intercalatum are sympatric and able to hybridize.