True Seeds Research Articles

Evaluating the role of insect pollinators in the viability of true seeds of shallot in tropical agroecosystems

Pollen transfer in tropical agroecosystems to increase seed production has received limited research, notably on shallot pollination and insect pollinators. This study evaluated how insect pollinators optimize shallot seed production in tropical agroecosystems, i.e. Batu and Malang Districts in Indonesia. This study was conducted from June to October in 2023. We examined pollinator diversity, foraging behavior, and the effectiveness of dominating insect pollinators during umbel flower anthesis, as well as visiting insect foraging and visiting patterns. We assessed pollinator effectiveness by comparing visitation rates under four treatments. A total of 21 insect species belonging to three orders visited the shallot flowers, of which 14 species have the potential to act as pollinators. Apis cerana Fabricius, 1793 (Hymenoptera: Apidae) and Lucilia sericata (Meigen, 1826) (Diptera: Calliphoridae) emerged as potentially effective pollinators. Air temperature significantly influenced pollinator activity in visiting anthesis umbels. Evaluations of pollinator efficiency showed that A. cerana was more efficient than L. sericata in promoting the production of true shallot seed and has a significant role in ensuring high-quality pollination. This highlights the necessity of comprehending the specialized contributions of pollinators for shallot seed production.

Branching response to stem density and its impact on yield in hybrid potato grown from true seeds and seedling tubers

ContextHybrid potato crops can be grown from true potato seeds or from seedling tubers. True-seed-grown plants produce lower marketable tuber yield than seedling-tuber-grown plants, because of their low early vigour and distinct growth and development patterns, notably in term of main stem number and stem branching. These differences are pivotal for yield formation but their impacts on crop performance and yield are not well understood. ObjectivesWe quantified the differences between the propagule types (true seeds vs seedling tubers) in their branching responses to stem density and assessed to what extent these differences contribute to differences in crop development and tuber production. MethodsTwo field experiments were conducted in different years, planting transplants from true seeds and pre-sprouted seedling tubers from the same genotype, while controlling their stem density per unit area. Responses in stem branching and biomass partitioning to stem density were quantified on individual main stems, followed by an evaluation of the impact of these responses on crop performance. ResultsOn individual main stems in both propagule types, higher stem density decreased branch development, decreased the number of branches above- and belowground, resulted in shifts in aboveground branch distribution towards lower branching orders, and led to smaller tuber sizes. However, such branching responses were stronger in true-seed-grown plants than in seedling-tuber-grown plants. At crop level, differences between propagule types were significant in canopy duration, number of tubers, tuber size distribution and marketable yield, but there was no stem density effect. ConclusionOur results emphasized the differences between propagule types in branching and its impact on crop development and tuber yield, due to the absence of stem density effects. Propagule type effects could be attributed to intrinsic differences between propagule types in branching control, growth habit and source-sink relations. These effects are relevant for hybrid potato breeding and require further research. Management practices were partly responsible for year-to-year differences in branching and yield formation, which highlights their significance for hybrid potato production.

Identification and validation of reference genes for gene expression study using Quantitative Real-Time PCR in shallot (Allium cepa L. Aggregatum group) based on bulb development phase

Abstract. Sulistyaningsih E, Sawitri WD, Handayani VDS, Wicaksono AW, Silalahi CM, Murti RH. 2024. Identification and validation of reference genes for gene expression study using Quantitative Real-Time PCR in shallot (Allium cepa L. Aggregatum group) based on bulb development phase. Biodiversitas 25: 2645-2651. Shallot (Allium cepa L. Aggregatum group) is cultivated vegetatively using bulbs (produce many bulbs) and generatively using TSS (True Seed of Shallot) which tends to produce single bulbs. Bulb aggregation is influenced by activity of genes and the gene expression could be analyzed using quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). The qRT-PCR analysis requires reference gene data (housekeeping gene) as a comparison gene against our target gene. This study aimed to select and validate three housekeeping genes in shallot as an initial study for qRT-PCR analysis. The research flow began with the preparation of shallot 'TukTuk' leaves and bulb samples in bulb formation from bulb initial phase to mature phase. Furthermore, a specific primer design based on actin, tubulin, and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene sequences were obtained from gene bank data. The results showed that the actin, tubulin, and GAPDH genes were successfully amplified and the products were 142 bp, 116 bp, and 136 bp in size, respectively and the genes were expressed almost constantly in leaves and bulbs in all phases of bulb formation. The tubulin gene had the potential as a reference gene for qRT-PCR analysis in shallot with the most consistently expressed.

New Frontiers in Potato Breeding: Tinkering with Reproductive Genes and Apomixis.

Potato is the most important non-cereal crop worldwide, and, yet, genetic gains in potato have been traditionally delayed by the crop's biology, mostly the genetic heterozygosity of autotetraploid cultivars and the intricacies of the reproductive system. Novel site-directed genetic modification techniques provide opportunities for designing climate-smart cultivars, but they also pose new possibilities (and challenges) for breeding potato. As potato species show a remarkable reproductive diversity, and their ovules have a propensity to develop apomixis-like phenotypes, tinkering with reproductive genes in potato is opening new frontiers in potato breeding. Developing diploid varieties instead of tetraploid ones has been proposed as an alternative way to fill the gap in genetic gain, that is being achieved by using gene-edited self-compatible genotypes and inbred lines to exploit hybrid seed technology. In a similar way, modulating the formation of unreduced gametes and synthesizing apomixis in diploid or tetraploid potatoes may help to reinforce the transition to a diploid hybrid crop or enhance introgression schemes and fix highly heterozygous genotypes in tetraploid varieties. In any case, the induction of apomixis-like phenotypes will shorten the time and costs of developing new varieties by allowing the multi-generational propagation through true seeds. In this review, we summarize the current knowledge on potato reproductive phenotypes and underlying genes, discuss the advantages and disadvantages of using potato's natural variability to modulate reproductive steps during seed formation, and consider strategies to synthesize apomixis. However, before we can fully modulate the reproductive phenotypes, we need to understand the genetic basis of such diversity. Finally, we visualize an active, central role for genebanks in this endeavor by phenotyping properly genotyped genebank accessions and new introductions to provide scientists and breeders with reliable data and resources for developing innovations to exploit market opportunities.

Technical feasibility and economic benefit of combined shallot seedlings techniques in Indonesia

Abstract One of the important factors in the success of True Seed of Shallot (TSS)-based shallot production is the right seeding technology. The study aimed to obtain appropriate nursery techniques for producing high-quality seedlings to increase shallot productivity. The experiment was conducted in Cirebon Regency, West Java, Indonesia, from May to October 2021, using a factorial randomized block design with three treatment factors and three replications. They consisted of shallot varieties (V) (Trisula, Bima, Lokananta, and Maserati); seedlings age (U) (45 and 60 days); and seedling population density (P) (5, 7.5, and 10 g m−2 of TSS). The results revealed that seedling performance was negatively correlated to the bulb yield and revenue cost ratio (R/C). The use of young seedlings enhanced bulb production and R/C ratio in all varieties but had varied effects on cluster alterations in Maserati, Bima, and Trisula varieties. Young Lokananta seedlings prepared in the nursery at a seed density of 7.5 g m−2 proved to be the best treatment to generate the highest bulb production (39.92 t ha−1) and the highest R/C (3.62). Farmers are expected to implement seedling preparation techniques using young seedlings and managing seed populations in diverse varieties to maximize bulb production and R/C.

Pollination efficiency and foraging behavior of Bombus pauloensis (Hymenoptera: Apidae) on two highbush blueberry cultivars (Vaccinium corymbosum)

Bombus pauloensis Friese is a promising managed bumblebee that can pollinate crops in South America. Highbush blueberry (Vaccinium corymbosum L.) is a recently introduced and economically promising crop cultivated in open fields or greenhouses in Colombia. Although this crop is known to be pollinator-dependent, the efficiency of local pollinators in this geographic area has yet to be established. This study aimed to establish the pollination effectiveness and foraging behavior of B. pauloensis in two of the most common cultivars of highbush blueberries planted in a high Andean region of Colombia. We hand-reared and located B. pauloensis colonies in two different plantations of Sharpblue (open field) and Biloxi (greenhouse) cultivars. The time spent per flower and the number of flowers visited per minute of 300 foragers were registered to characterize the foraging behavior in both cultivars. Pollen analysis was performed once from corbicular loads, larvae, larval cells, and colony feces to identify the pollen sources collected by colonies located in the Sharpblue crop. Analysis of fruit quality was performed to establish the effect of B. pauloensis pollination. Foragers visited blueberry flowers with a corolla aperture of more than 3mm in both cultivars but spent more time visiting Biloxi than Sharpblue flowers. B. pauloensis pollination reduced the ripening time and increased the fresh and dry weight and the number of true seeds in both cultivars. Our results provide evidence that B. pauloensis pollination can improve the fruit quality in the blueberry cultivars evaluated here in Colombia, making it an efficient native pollinator for a promising commercial species.

A k-mer-based bulked segregant analysis approach to map seed traits in unphased heterozygous potato genomes.

High-throughput sequencing-based methods for bulked segregant analysis (BSA) allow for the rapid identification of genetic markers associated with traits of interest. BSA studies have successfully identified qualitative (binary) and quantitative trait loci (QTLs) using QTL mapping. However, most require population structures that fit the models available and a reference genome. Instead, high-throughput short-read sequencing can be combined with BSA of k-mers (BSA-k-mer) to map traits that appear refractory to standard approaches. This method can be applied to any organism and is particularly useful for species with genomes diverged from the closest sequenced genome. It is also instrumental when dealing with highly heterozygous and potentially polyploid genomes without phased haplotype assemblies and for which a single haplotype can control a trait. Finally, it is flexible in terms of population structure. Here, we apply the BSA-k-mer method for the rapid identification of candidate regions related to seed spot and seed size in diploid potato. Using a mixture of F1 and F2 individuals from a cross between 2 highly heterozygous parents, candidate sequences were identified for each trait using the BSA-k-mer approach. Using parental reads, we were able to determine the parental origin of the loci. Finally, we mapped the identified k-mers to a closely related potato genome to validate the method and determine the genomic loci underlying these sequences. The location identified for the seed spot matches with previously identified loci associated with pigmentation in potato. The loci associated with seed size are novel. Both loci are relevant in future breeding toward true seeds in potato.

Evaluation of Dormancy Mechanism in Teak (Tectona grandis Linn.f) True Seeds Collected from Multiple Provenances and Forest Types of India

Teak drupes were collected from seven geographical locations spread over four forest types (dry deciduous, moist deciduous, very moist deciduous, and semi-deciduous) from India. In order to study the dormancy mechanism associated with teak true seeds. The true seeds present inside the drupes from each provenance were extracted without causing any damage to the true seeds. The extracted true seeds were used to study the morphological and physiological characteristics. The true seeds were carefully inoculated in MS medium to observe germination. Twenty-eight days after sowing, the result revealed that Andhra Pradesh provenance recorded the highest true seed germination of 58 percent compared to all other provenances. These results clearly indicate that not only physical and mechanical dormancy is involved in teak for decreased germination but also morphological/physiological dormancy plays a major role in teak true seed germination.

Quantifying differences in plant architectural development between hybrid potato (Solanum tuberosum) plants grown from two types of propagules.

Plants can propagate generatively and vegetatively. The type of propagation and the resulting propagule can influence the growth of the plants, such as plant architectural development and pattern of biomass allocation. Potato is a species that can reproduce through both types of propagation: through true botanical seeds and seed tubers. The consequences of propagule type on the plant architectural development and biomass partitioning in potatoes are not well known. We quantified architectural differences between plants grown from these two types of propagules from the same genotype, explicitly analysing branching dynamics above and below ground, and related these differences to biomass allocation patterns. A greenhouse experiment was conducted, using potato plants of the same genotype but grown from two types of propagules: true seeds and seed tubers from a plant grown from true seed (seedling tuber). Architectural traits and biomass allocation to different organs were quantified at four developmental stages. Differences between true-seed-grown and seedling-tuber-grown plants were compared at the whole-plant level and at the level of individual stems and branches, including their number, size and location on the plant. A more branched and compact architecture was produced in true-seed-grown plants compared with seedling-tuber-grown plants. The architectural differences between plants grown from true seeds and seedling tubers appeared gradually and were attributed mainly to the divergent temporal-spatial distribution of lateral branches above and below ground on the main axis. The continual production of branches in true-seed-grown plants indicated their indeterminate growth habit, which was also reflected in a slower shift of biomass allocation from above- to below-ground branches, whereas the opposite trend was found in seedling-tuber-grown plants. In true-seed-grown plants, lateral branching was stronger and determined whole-plant architecture and plant function with regard to light interception and biomass production, compared with seedling-tuber-grown plants. This different role of branching indicates that a difference in preference between clonal and sexual reproduction might exist. The divergent branching behaviours in true-seed-grown and seedling-tuber-grown plants might be regulated by the different intensity of apical dominance, which suggests that the control of branching can depend on the propagule type.

Non True Seed Production Practices and Certification Requirements: A Review

Non True Seed Production Practices and Certification Requirements: A Review

VIABILITAS DAN VIGOR BERBAGAI VARIETAS TRUE SHALLOT SEED DENGAN PERENDAMAN JENIS ZAT PENGATUR TUMBUH (ZPT) ALAMI

One of the keys to successful shallot cultivation with True Seed of Shallot (TSS) is determined by viability and vigor at the nursery. The aim of the study was to determine the effect of varieties and types of natural Plant Growth Regulatory (PGR) on germination and TSS vigor index. The study was conducted at the Seed Technology Laboratory of the Agricultural Development Polytechnic of Yogyakarta Magelang in July 2021 using a factorial Completely Randomized Design (CRD). The first factor is shallot variety (V) consisting of 3 levels: V1 = Sanren, V2 = Maserati, and V3 = Lokananta. The second factor is Types of Natural plant Growth Regulators (Z) consisting of 4 types: Z0 = aquadest, Z1 = Shallot Extract, Z2 = bean sprout extract, and Z3 = young coconut water. Each treatment was repeated 3 times. Parameters observed were germination, growth speed and vigor index. Data analysis was carried out using a variance test (F test) and Duncan's multiple distance test (DMRT) with a level of 0.05. The results showed that the TSS variety significantly affected germination and growth speed. The type of natural PGR did not significantly affect the germination, but it did affect the growth speed. TSS varieties and natural PGR types significantly interacted with the vigor index parameter. The best vigor index was achieved when the Lokananta variety was treated with distilled water. Keywords: Shallot, bean sprouts, coconut water, germination, vigor.

Garlic Potyviruses Are Translocated to the True Seeds through the Vegetative and Reproductive Systems of the Mother Plant.

Garlic lost its ability to produce true seeds millennia ago, and today non-fertile commercial cultivars are propagated only vegetatively. Garlic viruses are commonly carried over from one generation of vegetative propagules to the other, while nematodes and arthropods further transmit the pathogens from infected to healthy plants. A recent breakthrough in the production of true (botanical) garlic seeds resulted in rapid scientific progress, but the question of whether viruses are transmitted via seeds remains open and is important for the further development of commercial seed production. We combined morpho-physiological analysis, fluorescence in situ hybridization (FISH), and PCR analysis to follow potyvirus localization and translocation within garlic fertile plants and seeds. Spatial distribution was recorded in both vegetative and reproductive organs. We conclude that garlic potyviruses are translocated to the seeds from the infected mother plant during flower development and post-fertilization, while pollen remains virus-free and does not contribute to seed infection. Therefore, the main practical goal for virus-clean seed production in garlic is the careful maintenance of virus-free mother plants. Although garlic pollen is free of potyviral infection, the male parents’ plants also need to be protected from contamination, since viral infection weakens plants, reducing flowering ability and pollen production.

Effect of ageing on in vitro true seed and in vivo drupe germination and its dormancy mechanism in teak (Tectona grandis Linn.f)

The germination percentage of teak seed is generally very poor due to its higher percentage of empty seed and poor seed viability. The viable seeds exhibit protracted germination behaviour due to their inherent seed dormancy and other physiochemical characteristics. Hence establishing a teak nursery for largescale plantation activities is a challenging task. This study was undertaken to study the effect of ageing on in vitro true seed and in vivo drupe germination and its dormancy mechanism in teak. Fresh, one-year and two-year stored drupes were used to represent different levels of ageing. Under in vivo conditions, poor drupe germination was observed in fresh drupes (3%) and germination percentage was increased when the drupes were subjected to ageing for one year (17%) or two years (32%). When true seeds separated from fresh drupes and germinated under in vitro conditions, enhanced germination (58.3%) was observed. Biochemical analysis showed that indole-3- acetic acid, indole butyric acid, abscisic acid and coumarin are not present in fresh, one year and two-year-old true seeds. The gibberellic acid was increased with an increase in ageing, but the GA3 did not influence the germination percent under in vitro conditions. Scanning electron microscope (SEM) image of fresh teak true seed showed that embryo tip was shrivelled, whereas one and two-year-old true seed embryo tip bulged; this was confirmed that one and two-year-old true seed embryos were matured and satisfied the after-ripening requirement. Nursery studies revealed that one and two-year-old drupes recorded the highest germination compared to fresh drupes.

Nondestructive high-throughput sugar beet fruit analysis using X-ray CT and deep learning

Sugar beet (Beta vulgaris L. ssp. vulgaris) accounts for roughly 20% of the global sugar production, with the remainder derived from sugar cane (Saccharum officinarum L.). To maximize sugar yield, high performing sugar beet varieties are needed, in combination with good agronomical practices. Delivering vigorous seeds to the market and meeting the highest quality standards is, therefore, essential. Seed vigor is highly determined by fruit morphology, with the main characteristics of interest being fruit and true seed size, pericarp morphology and fruit filling. Current methods for evaluating fruit morphology mostly rely on labor-intensive and destructive analyses. Here we present a high-throughput nondestructive method to quantitatively phenotype sugar beet fruit and true seeds using X-ray micro-CT imaging and deep learning. A 3D convolutional neural network was trained for the semantic segmentation of the pericarp, true seed and air in X-ray micro-CT scans. High average Dice scores of 0.996, 0.971 and 0.930 were found for the pericarp, true seed and air, respectively. Additionally, since farmers target single plants after emergence in the field, we present a method to identify whether sugar beet fruit are monogerm or contain more than one seed (bigerm). An excellent overall classification accuracy, false positive and false negative rate of respectively 98.6, 1.0and 1.8% were achieved. The presented methods have a high potential for integration into tools for breeding programs and the sample-wise monitoring and adjustment of production processes.

Invigoration Increased Quality and Storability of True Seed of Shallot (Allium ascalonicum L.)

Seed invigoration is a pre-planting seed treatment by balancing the seed water potential and stimulating their metabolic activities so that the seeds germinate simultaneously. In this study, invigoration treatments were applied to improve the quality of the true seeds of shallots (TSS) that had started to deteriorate. Invigoration increases the moisture content of the seeds so the seeds need to be re-dried to extend their storability. The aims of the study were to determine the best invigoration treatment and the drying method to maintain the benefit of invigoration, and to prolong TSS storability after invigoration and drying. This research was conducted at the Laboratory of Seed Quality Testing, IPB University, Indonesia, and consisted of three experiments, i.e., invigoration of deteriorating TSS to improve their viability and vigor, drying after invigoration to extend seed storability, and seed storability after invigoration and drying treatments. The first experiment was arranged in completely randomized design with one-factor (invigoration solutions), i.e. control, medium containing 3% KNO3, 50 ppm GA3, 0.5 % ZnSO4 or PEG6000 -10 bar. The second experiment was conducted using a two-factor completely randomized design, drying temperature (20˚C, 30˚C, and 40˚C), and drying duration (8 hours, 16 hours, 32 hours, and 48 hours). The third experiment was arranged in a nested design with two factors. The first factor was a seed storage condition, i.e., ambient temperature, air-conditioned room, and refrigerator. The second factor was seed packages, i.e., aluminum foil and polypropylene plastic. Non-invigorated seeds were used as control. The studies were conducted on two shallot varieties separately, “Trisula” and “Lokananta”, except in the third experiment which only used “Lokananta”. The results showed that invigoration in 3 % KNO3 and 50 ppm GA3 effectively improved the vigor of deteriorating TSS. Drying the seeds at 40˚C for 8 hours was the most effective method to reduce seed moisture content without reducing the benefit of invigoration. Storing the invigorated TSS in an air-conditioned room with aluminum foil packaging, or in a refrigerator with aluminum foil or plastic packaging until 14 weeks maintained the benefit of invigoration. The quality of the invigorated TSS was maintained until 14 weeks in an air-conditioned room with aluminum foil packaging, or in a refrigerator with aluminum

Clone Selection Based on Yield Components in the First Generation of 6/7 Clone X 101 Potato (Solanum tuberosum L.) Cross

Ege Üniversitesi Ziraat Fakültesi Tarla Bitkileri Bölümü’nde yürütülen patates ıslahı çalışmalarından seçilmiş olan iki patates (Solanum tuberosum L.) genotipinin melezinden (6/7 klonu x 101 (Nif)) elde edilen gerçek tohumlar 2019 yılında serada plastik saksılarda yetiştirilmiş ve hasat sonrasında klonların yumru sayısı, tek yumru ağırlığı ve tek bitki verimi değerleri ölçülmüştür. Seçilen klonlar 2020 yılında fideliklerde kontrol popülasyonu olarak yetiştirilmiştir. İncelenen 133 klona ait özellikler için varsayılan normal dağılış parametreleri saptanmış ve farklı seleksiyon şiddeti oranı (ì) seviyelerine ait popülasyon oluşturularak bu popülasyonlar tek aşamalı seleksiyon metoduna göre 2020 yılında fide yastıklarında yetiştirilmiş yumru sayısı, tek yumru ağırlığı ve bitki verimi özellikleri ölçülerek ortalamalar elde edilmiştir. Kontrol popülasyonu ortalamaları ile başlangıç popülasyonundaki ortalamalar karşılaştırılmış ve kazançlar bulunmuştur. Yapılan karşılaştırma ve değerlendirmeler sonucu elde edilen bulgulara göre; iki popülasyon arasında yumru sayısı, tek yumru ağırlığı ve bitki verimi için korelasyon değerlerinin seleksiyonuı olumlu etkileyeceği kabul edilebilir. 2. uygulanan seleksiyon sonucu, yumru sayısı için p=0,05 oranında en yüksek seleksiyon diferansiyeli başlangıç popülasyonu ve kontrol popülasyonu ortalaması ile kazanç sırasıyla 4,8; 8,9 ve 4,1 olarak elde edilmiştir. 3. tek yumru ağırlığı için en yüksek seleksiyon diferansiyeli, fidelik popülasyonu ortalaması ve kazanç sırasıyla düşük düzeydeki p=0,20’de 1,4 g; 10,9 g ve 9,5 ve p=0,25 oranında sırasıyla 1,2 g; 12,1 g ve 10,9 olmuştur. 4. bitki verimi için en yüksek seleksiyon diferansiyeli, fidelik popülasyonu ortalaması ve kazanç, p=0,10 oranında seleksiyonda sırasıyla 6,7 g; 94,9 g ve 8,2 ve p=0,15 oranında ise sırasıyla 5,9 g; 125,4 g ve 119,5 olmuştur. Sonuç olarak yumru sayısı ve bitki verimi için yüksek ve orta şiddette p=0,05; p=0,10 ve p=0,15 seviyelerinde uygulanacak seleksiyonun başarılı olduğu ortaya çıkmıştır. Tek yumru ağırlığı için düşük düzeyde uygulanan örneğin p=0,20 ve p=0,25 seviyelerde uygulanan seleksiyon başarılı görülmüştür. Patates ıslahında tek bitki verimi için uygulanan seleksiyonda orta düzeyde (p=0,15) seleksiyon ile yüksek verim elde edilmektedir.

Genome evolution and diversity of wild and cultivated potatoes

Potato (Solanum tuberosum L.) is the world’s most important non-cereal food crop, and the vast majority of commercially grown cultivars are highly heterozygous tetraploids. Advances in diploid hybrid breeding based on true seeds have the potential to revolutionize future potato breeding and production1–4. So far, relatively few studies have examined the genome evolution and diversity of wild and cultivated landrace potatoes, which limits the application of their diversity in potato breeding. Here we assemble 44 high-quality diploid potato genomes from 24 wild and 20 cultivated accessions that are representative of Solanum section Petota, the tuber-bearing clade, as well as 2 genomes from the neighbouring section, Etuberosum. Extensive discordance of phylogenomic relationships suggests the complexity of potato evolution. We find that the potato genome substantially expanded its repertoire of disease-resistance genes when compared with closely related seed-propagated solanaceous crops, indicative of the effect of tuber-based propagation strategies on the evolution of the potato genome. We discover a transcription factor that determines tuber identity and interacts with the mobile tuberization inductive signal SP6A. We also identify 561,433 high-confidence structural variants and construct a map of large inversions, which provides insights for improving inbred lines and precluding potential linkage drag, as exemplified by a 5.8-Mb inversion that is associated with carotenoid content in tubers. This study will accelerate hybrid potato breeding and enrich our understanding of the evolution and biology of potato as a global staple food crop.

The Study of Shallot Seedling from TSS (True Shallot Seed) on LCAC (Low-Cost Aeroponic Chamber)

True Seed Shallot (TSS) is the planting material beside bulbs that farmers in Indonesia have used. TSS give some benefit for farmer technically and economically. However, the farmer’s utilization of TSS is not used widely yet because there are constraints on the provision of shallot seeds from TSS, such as low seed growing percentage and seedling performance. This study aims to obtain the best seedling performance of shallot from TSS with LCAC (Low-Cost Aeroponic Chamber) technology. The experiment was conducted at the Plant Factory and Screen House, Leuwikopo, Department of Mechanical and Biosystems Engineering, IPB University, July to October 2021. The germination was carried out for seven days. After that, the shallot seedlings have given light source treatments. The factor was light sources, i.e., screen house (sunlight; as a control; used wick system hydroponic), white light, red-blue light, and custom light (LED in a controlled room with LCAC). The performance shallot seedling on sunlight source treatment gave the average plant height, the number of leaves higher than white, red-blue, and custom light on 3 and 4 weeks after sowing. The white light treatment gave the chlorophyll-a, chlorophyll-b, and total chlorophyll-a & b higher than the other light source treatments.

Planting Materials, Shading Effects, and Non-Destructive Estimation of Compound Leaf Area in Konjac (Amorphophallus Muelleri)

Konjac glucomannan has been commercially produced and used as functional food, food additives, food supplements, pharmaceutical and cosmetic, and biomaterials. Despite intensive and advance research at postharvest stage, knowledge on cultivation of konjac plants has been limited. This research covered current issues associated with selecting agronomically the most suitable planting material, shading effects on shoot emergence and growth characteristics, and non-destructive area estimation of the compound leaf in the konjac plants. Planting materials used were 81 true seeds, 81 bulbils and 81 cormels. Results of this study indicated that bulbil was a suitable planting material based on its early shoot emergence and size of above ground organs. Shading at 50 and 70 % exhibited a better performance in time of emergence and growth characteristics than konjac plant fully exposed to sunlight, even though the differences were not statistically significant. Total leaf blade area (LA) of the irregular konjac compound leaf can be accurately (R2 = 0.9932) and consistently estimated using the 0-intercept linear model and the multiplication product of total midrib length and average width of all leaflets (TLM×AWL) is used as predictor. The recommended formula is LA = 0.6761(TLM×AWL).
 HIGHLIGHTS
 
 Shoot emergence in konjac plant was significantly earlier if the true seed was used rather than bulbil and cormel as planting materials
 Plant grown using cormel and bulbil exhibited larger shoot and corm compared to those grown using true seed
 Shading at 50 and 70 % increased length of the pseudo-stem, total number of leaflet, and other morphological characters
 Total midrib length of all leaflets and average of all leaflet width (TLM×AWL) could be used as predictors for accurate LA estimation
 
 GRAPHICAL ABSTRACT

Breeding Diploid F1 Hybrid Potatoes for Propagation from Botanical Seed (TPS): Comparisons with Theory and Other Crops.

This paper reviews the progress and the way ahead in diploid F1 hybrid potato breeding by comparisons with expectations from the theory of inbreeding and crossbreeding, and experiences from other diploid outbreeding crops. Diploid potatoes can be converted from an outbreeding species, in which self-pollination is prevented by a gametophytic self-incompatibility system, into one where self-pollination is possible, either through a dominant self-incompatibility inhibitor gene (Sli) or knockout mutations in the incompatibility locus. As a result, diploid F1 hybrid breeding can be used to produce genetically uniform potato cultivars for propagation from true potato seeds by crossing two near-homozygous inbred lines, derived from a number of generations of self-pollination despite inbreeding depression. Molecular markers can be used to detect and remove deleterious recessive mutations of large effect, including those in tight repulsion linkage. Improvements to the inbred lines can be made by introducing and stacking genes and chromosome segments of large desirable effect from wild relatives by backcrossing. Improvements in quantitative traits require a number of cycles of inbreeding and crossbreeding. Seed production can be achieved by hand pollinations. F1 hybrid planting material can be delivered to farmers as true seeds or young plants, and mini-tubers derived from true seeds.