The effect of parental plant and washing materials on seed germination of F2 generation apple cactus (Cereus spp.)

Apple cactus (Cereus sp.) is a genus of cactus, and two species that are often crossed are long spines (Cereus jamacaru) and short spines (Cereus peruvianus). Those species have seeds with physical dormancy, that is, seed mucilage that can inhibit the germination process. This research aims to study the effect of parental plants and washing materials on the germination of F2 apple cactus seeds. This study used two-factor RCBD using 3 parental plants of the F2 generation of apple cactus (C. jamacaru open pollination, C. peruvianus × C. jamacaru, C. jamacaru × C. peruvianus) and 5 washing materials (without washing, pH 8, distilled water (pH 7), pH 5, and pH 9) which was carried out in 3 repetitions. The results showed that seeds of the cross C. jamacaru as female parent (C. jamacaru open pollination and C. jamacaru × C. peruvianus) produced better germination than seeds from the cross of C. peruvianus as female parent (C. peruvianus × C. jamacaru). Although the washing material didn’t significantly affect the germination of F2 apple cactus seeds, there was an influence of using pH 9 to minimize seed mucilage so that the extraction process was easier.

Remember or not? For how long can a clonal plant remember drought stress?

Stress can be remembered by plants in a form of ‘stress memory’ that can alter future phenotypes of previously stressed plants and even phenotypes of their offspring. It was shown that DNA methylation is among the mechanisms mediating the memory. It is not known for how long the memory is kept by plants. If the memory is long lasting, it can become maladaptive in situations when parental-offspring environment differ. We investigated for how long can a parental plant “remember” that it experienced a stress and pass the memory to its clonal offspring. We grew parental plants of three genotypes of Trifolium repens for five months either in control conditions or in control conditions that were interrupted with drought pulses applied for two months in four different time-slots. We also treated half of the parental plants with 5-azacytidine (5-azaC) to test for the potential role of DNA methylation in the stress memory. Then, we transplanted parental cuttings (ramets) individually to control environment and allowed them to produce offspring ramets for two months. The drought stress experienced by parents affected phenotypes of offspring ramets. Such a memory resulted in enhanced number of offspring side branches originating from plants that experienced drought stress maximally 6 weeks before their transplantation to control environment. We did not find any transgenerational memory in offspring of plants that experienced drought stress later than 6 weeks before their transplantation. 5-azaC also reduced the effect of transgenerational memory on offspring ramets. We confirmed that drought stress can trigger transgenerational memory in T. repens that is very likely mediated by DNA methylation. Most importantly, the memory was time limited and was gradually erased. We conclude that the time limited memory on environmental stress can be adaptive as climate tends to be variable and parental-offspring environmental conditions often do not match.

Detection of AtRKD4 Protein During Induction of Somatic Embryogenesis in Dendrobium lineale Rolfe Transgenic Orchids Carrying 35S::GR::AtRKD4

Dendrobium lineale is an Indonesian native orchid from the Spatulata section in Orchidaceae Family. This orchid is important because it is usually used as a parental plant in orchid breeding and is predicted to have a potential phytochemistry compound. In addition, in their natural habitat, this orchid is threatened due to forest exploitation and natural disaster. Therefore the precision mass propagation techniques for this orchid need to be conducted. Biotechnological approaches through inserting embryo gene such as AtRKD4 from Arabidopsis thaliana has already been successfully conducted. This study aims to check the integration stability of T-DNA harboring 35S::GR::AtRKD4 from ten selection transformants and to detect the existence of AtRKD4 protein after induction by Dexamethasone and/ Thidiazuron. The result showed that T-DNA were stably integrated into the genome of D. lineale transformants and the AtRKD4 protein with a molecular weight of 28.53 kDa was detected in D. lineale transformant plants after being induced by 15 µM DEX and 3 mgL-1 TDZ for 5 days.

ANALISIS HOMOGENITAS GENETIK KLON APEL (Malus spp.) HASIL PERBANYAKAN EX VITRO BERDASARKAN PENANDA SSR

Analysis of the Genetic Homogeneity of Apple (Malus spp.) Clones Propagated by Ex Vitro Culture Based on SSR Markers Propagation of apple plants (Malus spp.) vegetatively has the advantage of genetic homogeneity between clones and their parents. However, the possibility of cytological and off-type deviations persists during mass propagation. This study aims to analyze the genetic homogeneity of apple plants using SSR markers in ex vitro propagation techniques. Morphological observations between the parental plant and the ex vitro propagation derived clones and also among themselves did not show any differences. To analyze the genetic heterogeneity of these plants, 15 SSR primers were screened on 29 propagation clones of apple var. Anna and Manalagi. Genetic characters were scored for group analysis using Darwin 6.05. Eight SSR primers (IPA 2, IPA 3, IPA 4, 5 PA, 6 PA, 12 PA, 13 PA, and 14 PA) produced 82 clear and easily visible bands in the size range of 90-365 bp. This study successfully detected the uniformity of all band patterns from the plant samples. The SSR markers could be used to analyze the genetic stability of the ex vitro propagation of apple clones. Perbanyakan tanaman apel (Malus spp.) secara vegetatif memiliki keunggulan homogenitas genetik antara klon dengan induknya. Namun kemungkinan terjadi penyimpangan sitologi dan off type tetap ada saat perbanyakan massal. Penelitian ini bertujuan untuk menguji homogenitas genetik tanaman apel menggunakan penanda SSR pada teknik perbanyakan ex vitro. Pengamatan secara morfologi antara tanaman induk dengan hasil perbanyakan secara ex vitro dan dengan sesamannya tidak menunjukkan perbedaan. Untuk menganalisis homogenitas genetik tanaman ini kami menyaring 15 primer SSR pada 29 klon perbanyakan tanaman apel varietas Anna dan Manalagi. Karakter genetik dihitung untuk analisis kelompok menggunakan Darwin 6.05. Sebanyak 8 primer SSR (IPA 2, IPA 3, IPA 4, 5 PA, 6 PA, 12 PA, 13 PA, dan 14 PA) menghasilkan 82 pita yang jelas dan mudah terlihat dalam kisaran ukuran 90-365 bp. Studi ini juga berhasil mendeteksi keseragaman pola pita semua sampel tanaman. Penanda SSR dapat digunakan untuk analisis stabilitas genetik perbanyakan ex vitro dari tanaman apel.

An Assessment of the Lolium perenne (Perennial Ryegrass) Seedborne Microbiome across Cultivars, Time, and Biogeography: Implications for Microbiome Breeding

Research into the bacterial component of the seed microbiome has been intensifying, with the aim of understanding its structure and potential for exploitation. We previously studied the intergenerational seed microbiome of one cultivar of perennial ryegrass with and without one strain of the commercially deployed fungal endophyte Epichloë festucae var. lolii. The work described here expands on our previous study by exploring the bacterial seed microbiome of different commercial cultivar/Epichloë festucae var. lolii combinations in collections of single seeds from the harvest year 2016. In this dataset, a cultivar effect could be seen between the seed microbiomes from cultivars Alto and Trojan. The bacterial component of the seed microbiome from pooled seeds from a single cultivar/E. festucae var. lolii combination harvested from 13 seed production farms around Canterbury in the year 2018 was also studied. This dataset allows the effect of different production locations on the bacterial seed microbiome to be examined. By comparing the two sets of data, bacteria from the genera Pantoea, Pseudomonas, Duganella, Massilia, and an unknown Enterobacteriaceae were observed to be in common. This core bacterial microbiome was stable over time but could be affected by supplemental taxa derived from the growth environment of the parental plant; differing microbiomes were seen between different seed production farms. By comparison to a collection of bacterial isolates, we demonstrated that many of the members of the core microbiome were culturable. This allows for the possibility of exploiting these microbes in the future.

Sterculia apetala (Panama tree).

Sterculia apetala is a tree native the tropics and subtropics of North, Central and South America, grown as an ornamental and shade tree and cultivated for its timber and edible seeds. It is reported as invasive in Puerto Rico, Cuba and Hawaii. In Hawaii, numerous seedlings and saplings that were originally growing close to pineapple plantations are now slowly spreading into nearby areas. Without seed predation or animal dispersal the seeds fall close to the parental plant, leading to almost pure stands of seedlings and saplings. In Cuba it is regarded as a transformer species, due to its high seed production and high dispersal capacity.

Phasing and imputation of single nucleotide polymorphism data of missing parents of bi-parental plant populations

This paper presents an extension to a heuristic method for phasing and imputation of genotypes of descendants in bi-parental populations so that it can phase and impute genotypes of parents of bi-parental populations that are fully ungenotyped or partially genotyped. The imputed genotypes of the parent are then used to impute low-density genotyped descendants of the bi-parental population to high-density. The extension works in three steps. First, it identifies whether a parent has no or low-density genotypes available and it identifies all of its relatives that have high-density genotypes. Second, using the high-density information of relatives, it determines whether the parent is homozygous or heterozygous for a given locus. Third, it phases heterozygous positions of the parent by matching haplotypes to its relatives.We implemented the new algorithm in an extension of the AlphaPlantImptue software and tested its accuracy of imputing missing parent genotypes in simulated bi-parental populations from different scenarios. We also tested the accuracy of imputation of the missing parent’s descendants using the true genotype of the parent and compared this to using the imputed genotypes of the parent. Our results show that across all scenarios, the accuracy of imputation of a parent, measured as the correlation between true and imputed genotypes, was > 0.98 and did not drop below ∼ 0.96. The imputation accuracy of a parent was always higher when it was inbred than when it was outbred and when it had low-density genotypes. Including ancestors of the parent at HD, increasing the number of crosses and the number of high-density descendants all increased the accuracy of imputation. The high imputation accuracy achieved for the parent across all scenarios translated to little or no impact on the accuracy of imputation of its descendants at low-density.Key MessageNew fast and accurate method for phasing and imputation of SNP chip genotypes within diploid bi-parental plant populations.

Effects of Triploidization of Loquat [Eriobotrya japonica (Thunb.) Lindl.] on Flavonoids and Phenolics and Antioxidant Activities in Leaves and Flower Buds

Triploid loquat (2n = 3x = 51) has stronger growth vigor and larger leaves, flowers, and fruit compared with its diploid parental plant (2n = 2x = 34), but the effects of triploidization on the contents of flavonoids and phenolics in leaves and flowers, which are the most important antioxidant compounds for pharmacological applications, have not been reported. In this report, 58 triploid loquat genotypes and seven corresponding diploid parental cultivars were used to evaluate the effects of triploidization on the contents of total flavonoids and phenolics and the antioxidant activities of leaves and flower buds. The results showed that the contents of total flavonoids and phenolics and their corresponding antioxidant activities were higher in most of the triploid loquat genotypes than their diploid parents. The antioxidant activities of leaves and flower buds were significantly correlated with the total flavonoids and phenolics contents in both diploid loquat and triploid loquat. It could be inferred that triploidization could increase the contents of flavonoids and phenolics in leaves and flower buds of loquat. Notably, the contents of total flavonoids and phenolics of leaves in triploid genotype ‘H3/24’ were the highest, reaching 212.00 mg rutin equivalent (RE)/g DW and 93.06 mg gallic acid equivalents (GAE)/g DW, respectively, which were significantly higher than those previously reported. Such a valuable trait may be stacked with other triploid traits that are already established, such as larger vegetative organs and better tolerance to various stresses, as a feasible strategy for breeding loquat cultivars with high pharmaceutical potency.