Utilization of somatic fusion techniques for the development of HLB tolerant breeding resources employing the Australian finger lime (Citrus australasica)

The Australian finger lime is a unique citrus species that has gained importance due to its unique fruit characteristics and perceived tolerance to Huanglongbing (HLB), an often-fatal disease of citrus trees. In this study, we developed allotetraploid finger lime hybrids and cybrids by utilizing somatic cell fusion techniques to fuse diploid ‘OLL8’ sweet orange or ‘Page’ tangelo callus-derived protoplasts with finger lime (FL) mesophyll-derived protoplasts. Six somatic fusions were regenerated from the ‘OLL8’ + FL fusion, while three putative cybrids were regenerated from the ‘Page’ + FL fusion. Ploidy levels and nuclear-expressed sequence tag derived simple sequence repeat (EST-SSR) markers confirmed the somatic hybrid production, and mitochondrial DNA primer sets confirmed the cybrid nature. Several trees produced by the somatic fusion remained HLB negative even after 6 years of growth in an HLB-endemic environment. Pathogenesis related (PR) and other genes that are often upregulated in HLB-tolerant trees were also upregulated in our somatic fusions. These newly developed somatic fusions and cybrids could potentially be used as breeding parents to develop the next generation of improved HLB-tolerant rootstocks and scions.

Advancement in long-distance bird migration through individual plasticity in departure

Globally, bird migration is occurring earlier in the year, consistent with climate-related changes in breeding resources. Although often attributed to phenotypic plasticity, there is no clear demonstration of long-term population advancement in avian migration through individual plasticity. Using direct observations of bar-tailed godwits (Limosa lapponica) departing New Zealand on a 16,000-km journey to Alaska, we show that migration advanced by six days during 2008–2020, and that within-individual advancement was sufficient to explain this population-level change. However, in individuals tracked for the entire migration (50 total tracks of 36 individuals), earlier departure did not lead to earlier arrival or breeding in Alaska, due to prolonged stopovers in Asia. Moreover, changes in breeding-site phenology varied across Alaska, but were not reflected in within-population differences in advancement of migratory departure. We demonstrate that plastic responses can drive population-level changes in timing of long-distance migration, but also that behavioral and environmental constraints en route may yet limit adaptive responses to global change.

Interspecific Potato Somatic Hybrids Between Solanum Malmeanum and S. Tuberosum Provide Valuable Resources for Freezing-Tolerance Breeding

Freezing stress affects the geographic distribution, growth, and development of potato, resulting in loss of its yield. Solanum malmeanum , a diploid wild species with strong freezing tolerance, was fused with a freezing sensitive dihaploid S. tuberosum by somatic hybridization. In our study, 980 calli were obtained, and 248 differentiate shoots from the calli. Parental-specific SSR markers were used to analyze the chromosome composition of the randomly selected 80 regenerated plants, resulting in 51 somatic hybrids. Among them, 44 somatic hybrids were tested with ploidy analysis in the years 2016 and 2020. During subculture, the genomic ploidy levels changed due to the composition of the unstable chromosome in 56.82% of the somatic hybrids. Compared with the cultivated parent, somatic hybrids showed better freezing tolerance. After freezing-tolerant somatic hybrids were selected to backcross with cultivars, we obtained some valuable breeding resources with enhanced freezing tolerance while similar tuberization capacity close to cultivars. The correlation analysis shows that freezing tolerance has no relation with tuberization capacity, which indicates that they are controlled by independent genetic loci. In all, we successfully conducted the protoplast fusion between S. malmeanum and S. tuberosum for the first time, which provided valuable resources for freezing-tolerant breeding.

Evaluation of Genotypes and Association of Traits in Watermelon Across Two Southern Texas Locations

Watermelon is the most important horticultural crop in Texas and is grown across the state under diverse environments. Our study was conducted in the southern region of Texas to understand genotype-by-environment interactions and the contribution of yield components to yield. To accomplish this, twenty genotypes were evaluated for important traits and characteristics at two locations, Uvalde and Weslaco TX, for two years, 2018 and 2019. The genotypes were evaluated for total yield, total fruit count, total soluble solids, rind thickness, fruit length, diameter and weight. Genotype-by-environment (G x E) interaction was not significant, possibly due to similarity in climatic conditions and nutrient management practices. In the grouped analysis, cultivars Crimson Diamond, Sunshade and the breeding line TAM 2 had a higher total yield. Path analysis showed a high direct effect for total fruit count and fruit diameter of 0.89 and 0.85, respectively. However, total fruit count had a high indirect effect of −0.44. Fruit weight was the only trait that showed a significant (p < 0.01) correlation towards total yield at r = 0.58. Neither of the high direct effects, total fruit count and fruit diameter, had a significant correlation. The study inferred that breeding resources could be optimized by reducing the testing location to only one representative location for measured traits in southern Texas. The indirect selection of total fruit or fruit diameter could result in better yield. The study suggested selecting for optimum total fruit and fruit diameter for higher yield.

The Largess of Motherhood

This chapter assesses the reasons and limitations for large size in female anacondas. Considering how large females are—nearly five times the size of males—it is obvious that the evolutionary pressures for large size act more strongly on females than males. One aspect in which natural selection definitely favors large size in females has to do with reproductive output. The larger a female is, the more babies can develop in her body and the larger the reproductive output. Reproductive value, or lifetime reproductive success, is the number of potential offspring that an individual can leave in the population over its lifetime. There are costs animals must face when they make reproductive decisions. Some of these costs are dependent on fecundity and some of them are not, such as the risk of being preyed upon during mating or pregnancy. A young adult female that has just reached maturity is under two opposite pressures: one is to breed right away and secure a few babies into the next generation, and the other is to skip reproduction, grow larger, and make more babies in a later year. A female that is going to breed faces another decision: how to invest her breeding resources. She can produce a large number of neonates of small size or a few offspring of large size.

ПЛЕМЕННЫЕ РЕСУРСЫ МЯСНОГО СКОТОВОДСТВА РОССИИ

Представлен краткий анализ состояния племенных ресурсов мясного скотоводства России, проведена сравнительная оценка основных пород по комплексу признаков, характеризующих молочность коров, сохранность и интенсивность роста молодняка. Численность поголовья основных пород рассчитана на основе данных Ежегодников по племенной работе в мясном скотоводстве в хозяйствах Российской Федерации за 2015 и 2018 года по породной структуре и размещению пробонитированного скота по регионам. Племенной скот характеризуется более высоким продуктивным потенциалом по всему комплексу хозяйственно полезных признаков. Доля племенного скота в сельскохозяйственных организациях и К(Ф)Х сократилась с 18,9 до 17,4 %. Среди пород племенного поголовья скота высокой молочностью (220 кг и более) отличаются шаролезская, лимузинская, обрак и абердин-ангусская. Самым высоким выходом телят на 100 коров к отъему характеризуются калмыцкая (86 голов), казахская белоголовая (82 головы), галловейская (79 голов) и абердин-ангусская (71 голова) породы. По интенсивности роста молодняка лучшими показателями обладает скот пород обрак, симментальская мясная, лимузинская, шаролезкая и герефордская. Эти показатели пород имеют существенное различие по регионам, поэтому породное разнообразие является безусловным конкурентным преимуществом мясного скотоводства России. This article presents the analysis of breeding resources for Russian meat cattle industry and comparative assessment of main breeds by a set of characteristics that characterize the milk production of cows, the safety and growth rate of young animals. Based on data of breeds’ structure and breeding cattle’s placement by region, the number of main breeds’ livestock at the Russian Federation was calculated. To assess the number of main breeds’ livestock, we used the data from Yearbook of breeding work at dairy and meat cattle breeding in the Russian Federation for 2015 and 2018. Breeding livestock is characterized by higher productive potential for the entire range of economically useful features. The share of breeding livestock at agricultural organizations decreased from 18.9 % in 2015 to 17.4 % in 2018. The Charolaise breed, Limousine, Aubrac and Aberdeen Angus are characterized by high milk yield (220 kg or more). The highest yield of calves for weaning per 100 cows have Kalmyk breed (86 heads), Kazakh White-headed (82 heads), Galloway (79 heads) and Aberdeen Angus (71 heads). According to the intensity of young animals’ growth, the best indicators have Aubrac breed, Simmental meat, Charolaise, Limousine and Hereford. These indicators of breeds have a significant difference by region, so the breed diversity is the absolute competitive advantage of meat cattle breeding at Russian Federation.

Development of rice pre-breeding resources with blast resistance

Within the framework of this study, the first Russian-Chinese joint program for development of rice varieties with long-term blast resistance was launched on the basis of rice germplasm exchange and the subsequent comprehensive study of the obtained breeding samples, hybridization of Russian and Chinese varieties with specified traits. The genetic diversity of the Chinese rice samples obtained by exchange was studied by biological and morphological traits of plants, taxonomic belonging to a botanical variety, elements of the yield structure, and resistance to lodging. 31 hybrid combinations (F1) from the crossing of Russian and Chinese varieties were used to obtain the BC1 generation. The technologies of cultivation of isolated rice anthers in vitro have been optimized in relation to Chinese genotypes in order to accelerate the genetic stabilization of breeding material obtained from crossing. Phenotyping of Russian and Chinese breeding samples was carried out on the basis of resistance to the local population of the blast pathogen (Magnaporthe grisea (T.T. Hebert) M.E. Barr)), on natural and artificial infectious backgrounds. DNA identification of genes for blast resistance was carried out for the same breeding samples. Based on the experimental data obtained, promising samples were selected - prototypes of new rice varieties.

СОВРЕМЕННЫЕ ПЛЕМЕННЫЕ РЕСУРСЫ ЯРОСЛАВСКОЙ ПОРОДЫ

Изучено современное состояние племенных ресурсов ярославской породы крупного рогатого скота. На современном этапе имеется достаточное количество генетических ресурсов, позволяющее совершенствовать породу при чистопородном (без прилития крови родственных пород) разведении. Племенная база ярославской породы представлена 11 племзаводами и 22 племрепродукторами. На 01.01.2019 г. в России имелось 42948 голов подконтрольного поголовья крупного рогатого скота ярославской породы, в том числе 26493 коров. Продуктивность коров в племенных хозяйствах составила 6256 кг молока с содержанием жира 4,24, белка 3,24, выход телят 89, средний возраст при выбытии 3,7 отелов. В племпредприятиях РФ, занимающихся разведением ярославской породы, содержалось 39 производителей ярославской породы, в том числе 17 чистопородных быков 8ми линий. Общий запас семени составлял 1069,3 тыс. доз, в том числе от чистопородных быков без прилития крови других пород 665,2 тыс. доз. В статье определены направления и методы работы с породой на перспективу для ее качественного улучшения и сохранения уникального отечественного генофонда в современных экономических условиях.The article presents the current state of breeding resources of Yaroslavl cattle breed in Russia. Today, there is a sufficient amount of genetic resources of the uterine and bovine livestock wich allows to improve the breed with purebred (without bloodshed of related breeds) breeding. The breeding base of the Yaroslavl breed is represented by 11 breeding plants and 22 breeding producers. There were 42948 heads of the controlled livestock of the Yaroslavl breed cattle on 01.01.2019 in Russia, including 26493 cows. Milk yield of cows in breeding farm swas 6256 kg of milk with fat content of 4,24, protein content of 3,24. The yield of calves is 89. The average age at retirement is 3,7 calving. In Russian breeding plants, engaged in breeding of the Yaroslavl breed, contained 39 sires of the Yaroslavl breed, including 17 animals purebred Yaroslavl of 8 lines. The total stock of seed was 1069,3 thousand doses, including purebred bulls without bloodshed of other breeds 665,2 thousand doses. The article defines the directions and methods of perspective work with the breed for its qualitative improvement and preservation of the unique domestic gene pool in modern economic conditions.