Short-Term Storability of Alginate-Encapsulated Persian Violet Microshoots for Germplasm Exchange

Microshoots have been widely used for micropropagation. It may be necessary to store microshoots for a short period of time, for example in germplasm exchange needing transport to other research groups. Here, we investigated the short-term storability of alginate-encapsulated Persian violet (Exacum affine Balf. f. ex Regel) microshoots at 4 °C and 25 °C. After storage, the encapsulated microshoots were sown on basal Murashige and Skoog medium for germination and viability determination using tetrazolium chloride staining. The results showed that one or five microshoots encapsulated with a single alginate layer could be stored at 4 °C for up to 30 days, while the percentages of germination and viability of the microshoots encapsulated with two layers of alginate were greatly reduced upon storage. This is the first report on the storability of alginate-encapsulated multiple microshoots, which could be a more efficient way to encapsulate microshoots used for short-term cold storage.

Can Cross-Country Genomic Predictions Be a Reasonable Strategy to Support Germplasm Exchange? – A Case Study With Hydrogen Cyanide in Cassava

Genomic prediction (GP) offers great opportunities for accelerated genetic gains by optimizing the breeding pipeline. One of the key factors to be considered is how the training populations (TP) are composed in terms of genetic improvement, kinship/origin, and their impacts on GP. Hydrogen cyanide content (HCN) is a determinant trait to guide cassava’s products usage and processing. This work aimed to achieve the following objectives: (i) evaluate the feasibility of using cross-country (CC) GP between germplasm’s of Embrapa Mandioca e Fruticultura (Embrapa, Brazil) and The International Institute of Tropical Agriculture (IITA, Nigeria) for HCN; (ii) provide an assessment of population structure for the joint dataset; (iii) estimate the genetic parameters based on single nucleotide polymorphisms (SNPs) and a haplotype-approach. Datasets of HCN from Embrapa and IITA breeding programs were analyzed, separately and jointly, with 1,230, 590, and 1,820 clones, respectively. After quality control, ∼14K SNPs were used for GP. The genomic estimated breeding values (GEBVs) were predicted based on SNP effects from analyses with TP composed of the following: (i) Embrapa genotypic and phenotypic data, (ii) IITA genotypic and phenotypic data, and (iii) the joint datasets. Comparisons on GEBVs’ estimation were made considering the hypothetical situation of not having the phenotypic characterization for a set of clones for a certain research institute/country and might need to use the markers’ effects that were trained with data from other research institutes/country’s germplasm to estimate their clones’ GEBV. Fixation index (FST) among the genetic groups identified within the joint dataset ranged from 0.002 to 0.091. The joint dataset provided an improved accuracy (0.8–0.85) compared to the prediction accuracy of either germplasm’s sources individually (0.51–0.67). CC GP proved to have potential use under the present study’s scenario, the correlation between GEBVs predicted with TP from Embrapa and IITA was 0.55 for Embrapa’s germplasm, whereas for IITA’s it was 0.1. This seems to be among the first attempts to evaluate the CC GP in plants. As such, a lot of useful new information was provided on the subject, which can guide new research on this very important and emerging field.

Germplasm Conservation as a Key for Food Security

Security of any country as well as the whole world can be ensure through the conservation of germplasm since they are genetic resources that can be used to prolong a population of an organism. Plant genetic resources (PGR) are the foundation of agriculture as well as food and nutritional security. The ICAR-NBPGR is key institution at national level for management of PGR in India under Indian Council of Agricultural Research (ICAR), New Delhi. India being rich in both flora and fauna germplasm diversity also have challenge of protecting its natural heritage. At the same time, we also have mutually beneficial strategies for germplasm exchange with other countries. The National Bureau of Plant Genetic Resources (NBPGR) activities include PGR exploration, collection, exchange, characteri- zation, evaluation, conservation and documentation. It also perform the responsibility to carry out quarantine of all imported PGR. NBPGR collects and acquires germplasm from various sources, conserves it in the Genebank, characterizes and evaluates it for different traits and provides ready material for breeders to develop varieties for farmers. At present, the National Genebank conserves more than 0.45 million accessions. NBPGR is responsible for identifying trait-specific pre-adapted climate resilient genotypes, promising material with disease resistance and quality traits which the breeders use for various crop improvement programmes. The prime focus area of research of NBPGR at present is is on characterization of ex situ conserved germplasm and detailed evaluation of prioritized crops for enhanced utilization. identification of novel genes and alleles for enhanced utilization of PGR; identification and deployment of germplasm/landraces.

Kinship networks of seed exchange shape spatial patterns of plant virus diversity

By structuring farmers’ informal networks of seed exchange, kinship systems play a key role in the dynamics of crop genetic diversity in smallholder farming systems. However, because many crop diseases are propagated through infected germplasm, local seed systems can also facilitate the dissemination of seedborne pathogens. Here, we investigate how the interplay of kinship systems and local networks of germplasm exchange influences the metapopulation dynamics of viruses responsible for the cassava mosaic disease (CMD), a major threat to food security in Africa. Combining anthropological, genetic and plant epidemiological data, we analyzed the genetic structure of local populations of the African cassava mosaic virus (ACMV), one of the main causal agents of CMD. Results reveal contrasted patterns of viral diversity in patrilineal and matrilineal communities, consistent with local modes of seed exchange. Our results demonstrate that plant virus ecosystems have also a cultural component and that social factors that shape regional seed exchange networks influence the genetic structure of plant virus populations.

The recent evolutionary rescue of a staple crop depended on over half a century of global germplasm exchange

Rapid environmental change can lead to extinction of populations or evolutionary rescue via genetic adaptation. In the past several years, smallholder and commercial cultivation of sorghum (Sorghum bicolor), a global cereal and forage crop, has been threatened by a global outbreak of an aggressive new biotype of sugarcane aphid (SCA; Melanaphis sacchari). Here we characterized genomic signatures of adaptation in a Haitian sorghum breeding population, which had been recently founded from admixed global germplasm, extensively intercrossed, and subjected to intense selection under SCA infestation. We conducted evolutionary population genomics analyses of 296 post-selection Haitian lines compared to 767 global accessions at 159,683 single nucleotide polymorphisms. Despite intense selection, the Haitian population retains high nucleotide diversity through much of the genome due to diverse founders and an intercrossing strategy. A genome-wide fixation (FST) scan and geographic analyses suggests that adaptation to SCA in the Haiti is conferred by a globally-rare East African allele of RMES1, which has also spread to breeding programs in Africa, Asia, and the Americas. De novo genome sequencing data for SCA resistant and susceptible lines revealed putative causative variants at RMES1. Convenient low-cost markers were developed from the RMES1 selective sweep and successfully predicted resistance in independent U.S. x African breeding lines and eight U.S. commercial and public breeding programs, demonstrating the global relevance of the findings. Together, the findings highlight the potential of evolutionary genomics to develop adaptive trait breeding technology and the value of global germplasm exchange to facilitate evolutionary rescue.

Germplasm Conservation: Instrumental in Agricultural Biodiversity-A Review

Germplasm is a valuable natural resource in plant diversity that is crucial for its potential use. It provides knowledge about a species genetic composition. Germplasm protection strategies are not just planting hope threatened with extinction, they preserve medicinal and other essential plants on which survival rests. The successful use of genetic plant resources necessitates diligent collection, storage, analysis, documentation, and germplasm exchange. Slow growth cultures, cryopreservation, pollen and DNA banks, botanic gardens, genetic reserves and farmer’s fields are few conservation techniques. However, usage of an in vitro procedure with any chance of genetic instability leads to the destruction of the entire substance. Improved understanding of basic regeneration biology would, in turn, undoubtedly increase the capacity to regenerate plants from in vitro harvested explants, thus expanding selection possibilities. Germplasm conservation seeks to conserve endangered and vulnerable plant species worldwide for future proliferation and development; it is also the bedrock of agricultural production.

Mobilization of plant genetic resources from South and Southeast Asia

The article is devoted to the replenishment of the VIR collection with plant genetic resources from the territories of the Philippines, Burma, Laos and Vietnam as a result of plant explorations, seed requests and germplasm exchange. In total, four collecting missions were sent to this region in the late 1970s and 1980s. Through their efforts, 2668 germplasm samples were collected and delivered to the Institute. The most numerous were the accessions of grain legumes (916), followed by vegetables (835) and groat crops (653). In addition to direct collection, the Institute was constantly engaged in requesting plant germplasm. In the prewar period, from 1925 to 1941, 396 accessions of cereal, groat, grain legume, vegetable, industrial and fruit crops were received from Burma, Vietnam, French Indochina (Laos since 1949) and the Philippines. From 1946 to 2019, 7928 accessions were added, with the largest number shipped from Vietnam (7840). Such a huge number can be explained by the activities of the Soviet breeding stations in Lai Châu Province, Northern Vietnam, and near Ho Chi Minh City, Southern Vietnam, in the 1980s and early 1990s. It should be noted that significantly fewer wild species and crop wild relatives were mobilized from these countries than from India, Indonesia and Ceylon – about 100 spp., or 10,992 accessions. Altogether, collecting teams brought from the South Asian tropical center of crop origin 18,594 germplasm samples, most of which were groat crops (4521). The prewar seed requests yielded 3520 accessions, with 1022 representing tropical woody, ornamental and medicinal plants from botanical gardens. Requests for germplasm from 1946 to the present time resulted in adding 16,687 accessions to the collection, half of which were groat crops (rice, maize and sorghum). A total of 39,161 accessions were received from the region.