Effect of Pollen Genotype, Temperature and Period of Storage on In Vitro Germinability and In Vivo Seed Set in Chrysanthemum—Preliminary Study

Among many challenges in chrysanthemum cross-breeding, the access to viable pollen for hybridization of cultivars distant in location and different in flowering time is required. Low pollen viability along with incompatibility are mainly responsible for low seed set in modern chrysanthemum cultivars. The aim of the study was to test various temperatures and periods of pollen storage of Chrysanthemum × morifolium in order to elaborate the method of chrysanthemum pollen preservation for cross-breeding purposes. In the first experiment, in vitro pollen germination of four cultivars was investigated following storage at 20 °C, 4 °C, −20 °C, and −80 °C, for one, four, and eight weeks. The second experiment focused on in vivo seed set after one week pollen treatment with 20 °C, 4 °C, −20 °C, and −80 °C (three pollen donor cultivars tested). Pollen in vitro germinability, as well as seed set efficiency, was generally low and cultivar dependent. Independent of the period of storage, stored pollen germinability was lower (5.30–6.63%) than fresh pollen (8.15%). Incubation of pollen in −80 °C significantly increased pollen germinability (9.80%), as well as seed set efficiency in comparison to control (19.28% and 10.21%, respectively) provided the cultivars are compatible. Among cultivars, the highest germinability of pollen was found in ‘Brda’ and ‘Donna’ (8.2% and 8.23%, respectively), while ‘Bydgoszczanka’ showed the lowest germinability (2.97%). There were also pollen genotype dependent effects in in vivo seed set efficiency, which was highest in ’Brda’ (17.57%) and much lower in ‘Jutrzenka’ and ‘Polka’ (1.34% and 0.39%, respectively), which contributed to the incompatibility of crossed cultivars rather than pollen viability.

Transcriptomic Analysis Reveals Key Candidate Genes Related to Seed Abortion in Chinese Jujube (Ziziphus jujuba Mill.)

Background: Seed abortion is a common phenomenon in Chinese jujube that seriously hinders the process of cross-breeding. However, the molecular mechanisms of seed abortion remain unclear in jujube. Methods: Here, we performed transcriptome sequencing using eight flower and fruit tissues at different developmental stages in Ziziphus jujuba Mill. ‘Zhongqiusucui’ to identify key genes related to seed abortion. Histological analysis revealed a critical developmental process of embryo abortion after fertilization. Results: Comparisons of gene expression revealed a total of 14,012 differentially expressed genes. Functional enrichment analyses of differentially expressed genes between various sample types uncovered several important biological processes, such as embryo development, cellular metabolism, and stress response, that were potentially involved in the regulation of seed abortion. Furthermore, gene co-expression network analysis revealed a suite of potential key genes related to ovule and seed development. We focused on three types of candidate genes, agamous subfamily genes, plant ATP-binding cassette subfamily G transporters, and metacaspase enzymes, and showed that the expression profiles of some members were associated with embryo abortion. Conclusions: This work generates a comprehensive gene expression data source for unraveling the molecular mechanisms of seed abortion and aids future cross-breeding efforts in jujube.

Business feasibility of several PS-01 hybrid silkworms (Bombix mori L.) cultivation scheme

Forest Research and Development Center has developed technology to increase productivity of sericulture through selection of types and varieties and cross-breeding to obtain superior hybrids. One of the superior hybrids produced is superior silkworm PS-01. The use of PS-01 hybrid silkworm seeds has been officially carried out with the Minister of Forestry Decree Number 794 I Menhut-II/2013 concerning the Release of PS-01 Hybrid Silkworm (Bombyx Mory L) Seeds. Several variations in the cultivation of the PS-01 hybrid silkworm in the field result in several cultivation schemes. This study aims to assess feasibility of several of PS-01 hybrid silkworm cultivation schemes. The research is conducted at KTH Bina Mandiri Sukabumi. Data and information are obtained through in-depth interviews with several farmer group members Bina Mandiri Sukabumi, owner and manager of PT Begawan Nusantara as a partner of KTH, which cultivates PS-01 silkworm seeds. Data are analyzed descriptively and qualitatively. Feasibility of PS-01 hybrid silkworm cultivation business is assessed using several criteria, namely NPV, BCR, IRR, and BEP, during the 10-year business cycle. The results of financial analysis on four silkworm cultivation schemes using PS-01 hybrid silkworm seeds show Schema I : KTH farmers buy PS-01 hybrid silkworm eggs and sell their products in cocoons; it is not feasible; Schema II : KTH farmers buy PS-01 hybrid silkworm egg seeds and sell their products in the form of yarn, and it is feasible; Schema III : KTH farmers do not purchase PS-01 hybrid silkworm eggs and sell their products in the form of cocoons; it is not feasible; Schema IV. In a partnership scheme, KTH farmers are assisted with silkworm eggs, consumable operational materials, farmers receive maintenance assistance up to the 3rd instar, and the sale of the produce in the form of cocoons is feasible.

Characterization of an APP/tau rat model of Alzheimer’s disease by positron emission tomography and immunofluorescent labeling

Background To better understand the etiology and pathomechanisms of Alzheimer’s disease, several transgenic animal models that overexpress human tau or human amyloid-beta (Aβ) have been developed. In the present study, we generated a novel transgenic rat model by cross-breeding amyloid precursor protein (APP) rats with tau rats. We characterized this model by performing positron emission tomography scans combined with immunofluorescent labeling and cerebrospinal fluid analyses. Methods APP/Tau rats were generated by cross-breeding male McGill-R-Thy1-APP transgenic rats with female hTau-40/P301L transgenic rats. APP/Tau double transgenic rats and non-transgenic (ntg) littermates aged 7, 13, and 21 months were subjected to dynamic [11C] PiB scan and dynamic [18F]THK-5317 scans. For regional brain analysis, a template was generated from anatomical MR images of selected animals, which was co-registered with the PET images. Regional analysis was performed by application of the simplified reference tissue model ([11C]PiB data), whereas [18F]THK-5317 data were analyzed using a 2-tissue compartment model and Logan graphical analysis. In addition, immunofluorescent labeling (tau, amyloid) and cerebrospinal fluid analyses were performed. Results [11C]PiB binding potential (BPND) and [18F]THK-5317 volume of distribution (VT) showed an increase with age in several brain regions in the APP/Tau group but not in the ntg control group. Immunohistochemical analysis of brain slices of PET-scanned animals revealed a positive correlation between Aβ labeling and [11C]PiB regional BPND. Tau staining yielded a trend towards higher levels in the cortex and hippocampus of APP/Tau rats compared with ntg littermates, but without reaching statistical significance. No correlation was found between tau immunofluorescence labeling results and the respective [18F]THK-5317 VT values. Conclusions We thoroughly characterized a novel APP/Tau rat model using combined PET imaging and immunofluorescence analysis. We observed an age-related increase in [11C]PiB and [18F]THK-5317 binding in several brain regions in the APP/Tau group but not in the ntg group. Although we were able to reveal a positive correlation between amyloid labeling and [11C]PiB regional brain uptake, we observed relatively low human tau and amyloid fibril expression levels and a somewhat unstable brain pathology which questions the utility of this animal model for further studies.

The development of the reproductive organs of the hybrid grouper cantik (Epinephelus fuscoguttatus x E. polyphekadion)

Observation of the reproductive organs of the hybrid grouper cantik was carried out. Cantik grouper is the result of cross-breeding between female tiger grouper Epinephelus fuscoguttatus and male camouflage grouper E. polyphekadion. This study aimed to determine the development of the reproductive organs of cantik grouper. The observed test fishes were 3 fishes of Cantik grouper with a total length of 42 - 49 cm and a bodyweight of 1.45 - 2.26 kg. The parameters observed were the concentarion of estradiol and testosterone in the blood using the ELISA kit, gonad development, and histological maturity level of the gonads. The results showed that the hormone testosterone found in the sample cantik no 1 was 9353 pg/ml, while the hormone estradiol was found in all samples of beautiful grouper in the range of 291 - 1133 pg/ml. From the dissected fish, the gonads had developed and weighed 3.12 - 56.01 g and one sample had a fecundity of 265,800 eggs with an egg diameter of 360-520 micron. Gonadal histology shows oosit development at maturity levels I, II, and IV. This indicates that the crossbreeding between female tiger grouper and male camouflage grouper produces hybrid grouper cantik that are fertile, which is shown by their reproductive organs to have developed well.

The Influence of Eroding Djallonke Genotype on the Incidence of Diseases and Mortalities in Sahalian X Djallonke Cross-bred Sheep

Despite cross breeding of Djallonke and Sahelian sheep due to the higher growth rate and final body weight of the Sahelian breeds over the years, little scientific evidence exists on the ability of the crosses to withstand diseases compared to their Djallonke parents. A study involving 700 Djallonke and two crosses of the Djallonke and Sahelian breeds (50% Sahel × 50% Djallonke, 75% Sahel × 25% Djallonke) was conducted, and documented incidence of diseases, parasites and mortalities in these animals. Enteritis (82%), Ehrlichia ruminantium (6.2%) and orf (6.2%) were more prevalent in 25% Djallonke than both 100% and 50% Djallonkes. Similarly, pneumonia was more prevalent in 50% Djallonkes, individuals of all age groups and females than all other genotypes, adults and males, respectively. Enteritis prevalence was also higher in lambs and males than animals of all age groups and females, respectively. Coccidiosis was more prevalent in individuals of all age groups and males, than lambs and females, respectively. More abscess and trauma cases were found in males than females. Significantly higher levels of tapeworms and flea infestations were seen in lambs than weaners and adults. Conversely, more mange mite and tick infestations were seen in adults than weaners and lambs. Higher levels of mortalities were recorded in all other genotypes, lambs, females and in haemoncosis cases than in 100% Djallonke, all other age groups, males and taeniasis cases, respectively. The Sahel x Djalloke crosses are more susceptible to infectious diseases and record higher mortality rates than the pure Djallonke genotypes.

Commercial cross breeding of dairy cattle with beef bulls in Western Siberia

The results of commercial cross breeding of dairy cattle with meat bulls are presented. Scientific and economic experiments were carried out in Omsk and Novosibirsk regions. Ranked cows of the red steppe breed were selected for the experiment. They were artificially inseminated with the semen of bulls of the red steppe, Kalmyk and Hereford breeds. Bulls of each genotype were selected from the calves born and three groups were formed by the method of analogue groups: 1st control - the red steppe, 2nd experimental - crossbreed of Kalmyk × the red steppe, 3d experimental – crossbreed of Hereford × the red steppe. In the second experiment two groups were formed from castrated bulls of Simmental and Hereford breeds × Simmental hybrids: 1st control group of Simmental breed, 2nd experimental group - Hereford × Simmental hybrids. A highly reliable superiority in the live weight of young animals of the 2nd and 3d experimental groups was revealed. From the age of 9 to 15 months, it was 16.5-77.3 kg (p <0.05-0.001) compared to animals in the control group. In the group of the red steppe x Hereford, slaughter yield was 58.6%, which is higher than that of the first two groups, by 1.9 and 1.8% (p <0.05), the carcass weight was 209.3 kg, the red steppe - 172.2 kg (p <0.01). In the second experiment at the age of 8, 12, 15 and 18 months, the bulls of the 2nd experimental group outperformed the peers of the 1st control group by 15.2-29.4 kg (p <0.05-0.001). Their slaughter yield was higher than that of the control group, and accounted for 57.8%. In two experiments, crossbred groups of animals were characterized by a better meat productivity. Commercial crossbreeding of dairy cows with beef breeds of bulls allows to increase meat productivity and increase the population of the meat cattle.