Recipient Parent Research Articles

Development of Superior Fibre Quality Upland Cotton Cultivar Series 'Ravnaq' Using Marker-Assisted Selection.

Marker-assisted selection (MAS) helps to shorten breeding time as well as reduce breeding resources and efforts. In our MAS program, we have targeted one of previously reported LD-blocks with its simple sequence repeat (SSR) marker(s), putatively associated with, at least, four different fibre quality QTLs such as fibre length, strength, micronaire and uniformity. In order to transfer targeted QTLs from a donor genotype to a cultivar of choice, we selected G. hirsutum donor genotypes L-141 and LN-1, possessing a fibre quality trait-associated LD-block from the chromosome 7/16. We crossed the donor lines with local elite G. hirsutum cultivars ‘Andijan-35’ and ‘Mekhnat’ as recipients. As a result, two segregating populations on LD-block of interest containing fibre QTLs were developed through backcrossing (BC) of F1 hybrids with their relative recipients (used as recurrent parents) up to five generations. In each BC and segregating BC1-5F1 populations, a transfer of targeted LD-block/QTLs was monitored using a highly polymorphic SSR marker, BNL1604 genotype. The homozygous cultivar genotypes with superior fibre quality and agronomic traits, bearing a targeted LD-block of interest, were individually selected from self-pollinated BC5F1 (BC5F2–5) population plants using the early-season PCR screening analysis of BNL1604 marker locus and the end-of-season fibre quality parameters. Only improved hybrids with superior fibre quality compared to original recipient parent were used for the next cycle of breeding. We successfully developed two novel MAS-derived cotton cultivars (named as ‘Ravnaq-1’ and ‘Ravnaq-2’) of BC5F5 generations. Both novel MAS cultivars possessed stronger and longer fibre as well as improved fibre uniformity and micronaire compared to the original recurrent parents, ‘Andijan-35’ and ‘Mekhnat’. Our efforts demonstrated a precise transfer of the same LD-block with, at least, four superior fibre QTLs in the two independent MAS breeding experiments exploiting different parental genotypes. Results exemplify the feasibility of MAS in cotton breeding.

QTL Analysis of Z414, a Chromosome Segment Substitution Line with Short, Wide Grains, and Substitution Mapping of qGL11 in Rice

Most agronomic traits of rice (Oryza sativa), such as grain length, are complex traits controlled by multiple genes. Chromosome segment substitution lines (CSSLs) are ideal materials for dissecting these complex traits. We developed the novel rice CSSL ‘Z414’, which has short, wide grains, from progeny of the recipient parent ‘Xihui 18’ (an indica restorer line) and the donor parent ‘Huhan 3’ (a japonica cultivar). Z414 contains four substitution segments with an average length of 3.04 Mb. Z414 displays seven traits that significantly differ from those of Xihui 18, including differences in grain length, width, and weight; degree of chalkiness; and brown rice rate. We identified seven quantitative trait loci (QTL) that are responsible for these differences in an F2 population from a cross between Xihui 18 and Z414. Among these, six QTL (qPL3, qGW5, qGL11, qRLW5, qRLW11, and qGWT5) were detected in newly developed single-segment substitution lines (SSSLs) S1–S6. In addition, four QTL (qGL3, qGL5, qCD3, and qCD5) were detected in S1 and S5. Analysis of these SSSLs attributed the short, wide grain trait of Z414 to qGL11, qGL3, qGL5, and qGW5. Substitution mapping delimited qGL11 within an 810-kb interval on chromosome 11. Sequencing, real time quantitative PCR, and cell morphology analysis revealed that qGL11 might be a novel QTL encoding the cyclin CycT1;3. Finally, pyramiding qGL3 (a = 0.43) and qGL11 (a = − 0.37) led to shorter grains in the dual-segment substitution line D2 and revealed that qGL11 is epistatic to qGL3. In addition, S1 and D2 exhibited different grain sizes and less chalkiness than Z414. In conclusion, the short grain phenotype of the CSSL Z414 is controlled by qGL11, qGL3, and qGL5. qGL11 might be a novel QTL encoding CycT1;3, whose specific role in regulating grain length was previously unknown, and qGL11 is epistatic to qGL3. S1 and D2 could potentially be used in hybrid rice breeding.

Identification of Candidate Genes for Lint Percentage and Fiber Quality Through QTL Mapping and Transcriptome Analysis in an Allotetraploid Interspecific Cotton CSSLs Population.

Upland cotton (Gossypium hirsutum) has long been an important fiber crop, but the narrow genetic diversity of modern G. hirsutum limits the potential for simultaneous improvement of yield and fiber quality. It is an effective approach to broaden the genetic base of G. hirsutum through introgression of novel alleles from G. barbadense with excellent fiber quality. In the present study, an interspecific chromosome segment substitution lines (CSSLs) population was established using G. barbadense cultivar Pima S-7 as the donor parent and G. hirsutum cultivar CCRI35 as the recipient parent. A total of 105 quantitative trait loci (QTL), including 85 QTL for fiber quality and 20 QTL for lint percentage (LP), were identified based on phenotypic data collected from four environments. Among these QTL, 25 stable QTL were detected in two or more environments, including four for LP, eleven for fiber length (FL), three for fiber strength (FS), six for fiber micronaire (FM), and one for fiber elongation (FE). Eleven QTL clusters were observed on nine chromosomes, of which seven QTL clusters harbored stable QTL. Moreover, eleven major QTL for fiber quality were verified through analysis of introgressed segments of the eight superior lines with the best comprehensive phenotypes. A total of 586 putative candidate genes were identified for 25 stable QTL associated with lint percentage and fiber quality through transcriptome analysis. Furthermore, three candidate genes for FL, GH_A08G1681 (GhSCPL40), GH_A12G2328 (GhPBL19), and GH_D02G0370 (GhHSP22.7), and one candidate gene for FM, GH_D05G1346 (GhAPG), were identified through RNA-Seq and qRT-PCR analysis. These results lay the foundation for understanding the molecular regulatory mechanism of fiber development and provide valuable information for marker-assisted selection (MAS) in cotton breeding.

Genetic Dissection of Rice Ratooning Ability Using an Introgression Line Population and Substitution Mapping of a Pleiotropic Quantitative Trait Locus qRA5.

Ratooning ability is a key factor that influences ratoon rice yield, in the area where light and temperature are not enough for second season rice. In the present study, an introgression line population derived from Minghui 63 as the recipient parent and 02428 as the donor parent was developed, and a high-density bin map containing 4568 bins was constructed. Nine ratooning-ability-related traits were measured, including maximum tiller number, panicle number, and grain yield per plant in the first season and ratoon season, as well as three secondary traits, maximum tiller number ratio, panicle number ratio, and grain yield ratio. A total of 22 main-effect QTLs were identified and explained for 3.26–18.63% of the phenotypic variations in the introgression line population. Three genomic regions, including 14.12–14.65 Mb on chromosome 5, 4.64–5.76 Mb on chromosome 8, and 10.64–15.52 Mb on chromosome 11, were identified to simultaneously control different ratooning-ability-related traits. Among them, qRA5 in the region of 14.12–14.65 Mb on chromosome 5 was validated for its pleiotropic effects on maximum tiller number and panicle number in the first season, as well as its maximum tiller number ratio, panicle number ratio, and grain yield ratio. Moreover, qRA5 was independent of genetic background and delimited into a 311.16 kb region by a substitution mapping approach. These results will help us better understand the genetic basis of rice ratooning ability and provide a valuable gene resource for breeding high-yield ratoon rice varieties.

Heterosis Derived From Nonadditive Effects of the BnFLC Homologs Coordinates Early Flowering and High Yield in Rapeseed (Brassica napus L.).

Early flowering facilitates crops to adapt multiple cropping systems or growing regions with a short frost-free season; however, it usually brings an obvious yield loss. In this study, we identified that the three genes, namely, BnFLC.A2, BnFLC.C2, and BnFLC.A3b, are the major determinants for the flowering time (FT) variation of two elite rapeseed (Brassica napus L.) accessions, i.e., 616A and R11. The early-flowering alleles (i.e., Bnflc.a2 and Bnflc.c2) and late-flowering allele (i.e., BnFLC.A3b) from R11 were introgressed into the recipient parent 616A through a breeding strategy of marker-assisted backcross, giving rise to eight homozygous near-isogenic lines (NILs) associated with these three loci and 19 NIL hybrids produced by the mutual crossing of these NILs. Phenotypic investigations showed that NILs displayed significant variations in both FT and plant yield (PY). Notably, genetic analysis indicated that BnFLC.A2, BnFLC.C2, and BnFLC.A3b have additive effects of 1.446, 1.365, and 1.361 g on PY, respectively, while their dominant effects reached 3.504, 2.991, and 3.284 g, respectively, indicating that the yield loss caused by early flowering can be successfully compensated by exploring the heterosis of FT genes in the hybrid NILs. Moreover, we further validated that the heterosis of FT genes in PY was also effective in non-NIL hybrids. The results demonstrate that the exploration of the potential heterosis underlying the FT genes can coordinate early flowering (maturation) and high yield in rapeseed (B. napus L.), providing an effective strategy for early flowering breeding in crops.

CG and CHG Methylation Contribute to the Transcriptional Control of OsPRR37-Output Genes in Rice.

Plant circadian clock coordinates endogenous transcriptional rhythms with diurnal changes of environmental cues. OsPRR37, a negative component in the rice circadian clock, reportedly regulates transcriptome rhythms, and agronomically important traits. However, the underlying regulatory mechanisms of OsPRR37-output genes remain largely unknown. In this study, whole genome bisulfite sequencing and high-throughput RNA sequencing were applied to verify the role of DNA methylation in the transcriptional control of OsPRR37-output genes. We found that the overexpression of OsPRR37 suppressed rice growth and altered cytosine methylations in CG and CHG sequence contexts in but not the CHH context (H represents A, T, or C). In total, 35 overlapping genes were identified, and 25 of them showed negative correlation between the methylation level and gene expression. The promoter of the hexokinase gene OsHXK1 was hypomethylated at both CG and CHG sites, and the expression of OsHXK1 was significantly increased. Meanwhile, the leaf starch content was consistently lower in OsPRR37 overexpression lines than in the recipient parent Guangluai 4. Further analysis with published data of time-course transcriptomes revealed that most overlapping genes showed peak expression phases from dusk to dawn. The genes involved in DNA methylation, methylation maintenance, and DNA demethylation were found to be actively expressed around dusk. A DNA glycosylase, namely ROS1A/DNG702, was probably the upstream candidate that demethylated the promoter of OsHXK1. Taken together, our results revealed that CG and CHG methylation contribute to the transcriptional regulation of OsPRR37-output genes, and hypomethylation of OsHXK1 leads to decreased starch content and reduced plant growth in rice.

Biofortified wheat: Harnessing genetic diversity for improved nutritional quality to eradicate hidden hunger

AbstractThe present study is based on backcross introgression lines carrying high grain zinc (Zn) quantitative trait loci (QTL) introgressed from domestic einkorn wheat (Triticum monococcum L.) and wild einkorn wheat (T. boeoticum) in the background of high‐yielding wheat (T. aestivum L.) cultivars of India. Initially, individual trials each for BC1F3 and BC2F3 progenies from different cross combinations were evaluated for grain Zn concentration, yellow pigment content (YPC) and agronomic traits. Highly promising BC1F3 and BC2F3 progenies were identified and advanced in off‐season as ear to progeny rows. A total of 42 BC1F5 and 43 BC2F5 derivatives were evaluated in a single trial where the BC1F5 progenies from recipient parent WH1105 and tetraploid parent Donor 2 were recorded with highest grain Zn (64.1–67.9 ppm) showing up to 35.8% enhancement over recipient. The highest grain YPC (5.35 ppm) was observed for BC1F5 progenies from the cross involving PBW703 (3.34 ppm) as recipient and Donor 7 (6.32 ppm) as tetraploid donor parent. Monitoring of backcross derivatives with the marker YP7A‐2 linked to yellow pigment gene Psy‐A1, also revealed nine lines positive for high yellow pigment allele (Psy‐A1c) indicating introgression from durum wheat (T. durum Desf.). Nineteen high Zn derivatives were shortlisted and selfed for 2 yr (2017–2018 and 2018–2019) to get desirable homozygosity and preliminary yield evaluation was conducted for two consecutive years (2019–2020 and 2020–2021). Introgression lines in the background of PBW698 (IL8 and IL17) were recorded with the highest Zn concentration (51.37 and 51.30 ppm) indicating 55.90% increment over recipient parent with good agronomic performance. These biofortified introgression wheat lines can contribute to mitigating the malnutrition among the masses in developing countries.

Fruit Composition of Eggplant Lines with Introgressions from the Wild Relative S. incanum: Interest for Breeding and Safety for Consumption

The wild species Solanum incanum has been used as a donor parent for the development of a set of eggplant introgression lines (ILs), which are of interest for breeding for stress tolerances and relevant morpho-agronomic traits but could also be useful for breeding for fruit quality, due to the generally higher content in health-promoting compounds of S. incanum. The use of eggplant ILs with introgressions from S. incanum requires ensuring that glycoalkaloids levels are below safety limits. We evaluated 25 fruit composition traits, including proximate composition, sugars, acids, phenolics, glycoalkaloids, and minerals in a set of 16 eggplant ILs with S. incanum, both parents and the F1, grown under two environments (open field and screenhouse). The results demonstrated that the parents were significantly different regarding most fruit composition traits. Large variation was found among the 16 ILs for all traits analyzed and a strong influence of the environment accounted for the variation of 17 out of the 25 traits evaluated. Although the S. incanum parent produced fruits with high levels of glycoalkaloids, the 16 ILs showed mean values of total glycoalkaloids below the currently accepted safety limit for human consumption (200 mg kg−1 fresh weight). Overall, the ILs produced fruits that are safe for consumption, with nutritional and functional quality similar to the recipient parent. Furthermore, six putative QTLs were detected spread over chromosomes 3 for crude protein, 5 for malic and total acids, and 7 for chlorogenic acid and solamargine, and potential candidate genes were spotted for most of them, which provide new relevant information for eggplant breeding.

Expanding the genetic variation of Brassica juncea by introgression of the Brassica rapa Genome.

Brassica juncea is an important vegetable and oil crop cultivated worldwide. To increase its genetic variation, we introgressed the A genome of Brassica rapa into B. juncea. We used three each of heading and semi-heading B. juncea accessions as recipient parents and a B. rapa line, B9008, as the donor parent. We obtained 101 BC1S1 lines in total with expanded phenotypic variations such as leafy head shapes. We developed 132 single-nucleotide polymorphism (SNP) markers that could distinguish the A genome of B. juncea from the B. rapa genome, and tracked the introgression of B. rapa segments in the new B. juncea germplasm. On average, 59.2% of the B. juncea A genome in the B. juncea introgression lines was covered by the donor segments. We also identified three markers whose donor genotype frequencies were significantly lower than the theoretical value, suggesting strong selection of the recipient genotype during the introgression process. We provide an effective strategy to evaluate the diversity of the new germplasm based on the combination of parental resequencing data and marker genotyping results. Further genetic analysis of 1642 SNPs showed that the genetic diversity of the new B. juncea germplasm with the introgressed B. rapa genome was significantly increased. This study illustrates the potential for expanding the genetic diversity of B. juncea through the introgression of the B. rapa genome.

Feeding Practice with Preventing Stunting on Keluarga Harapan Program Recipients in Pangkajene and Islands Districts

Background: Stunting is a condition where toddlers are shorter in length and height than their age. Percentage of stunting children in Pangkajene and Islands Districts with the highest percentage of 29.10% and the number of PKH recipients in 2019 as many as 16,498. The purpose of this study was to determine the relationship between Feeding Practice and the incidence of stunting on Keluarga Harapan Program recipients in Pangkajene and Islands Districts. Subjects and Method: The type of research used is observational with a cross sectional study design. The independent variable in this study is stunting and the dependent variable are feeding practice, Low Birth Weight and Economic status. The research location was carried out in Pangkajene and Islands Districts. The population in this study was all infants or toddlers from PKH recipient parents in Pangkajene and Islands Districts as many as 2,946 people in 2019 - 2021. The research sample was infants or toddlers from PKH parents who had participated in the Family Development Session as many as 71 people with the purposive method sampling. Primary data was collected using a questionnaire while secondary data was obtained from the social service of Pangkajene and Islands Districts. This study using the chi square test. Results: Incidence of stunting was higher in respondents with irregular feeding practice than in regular feeding practice (OR=0.54; CI 95% 0.33 to 0.91; p=0.024). The incidence of stunting was higher at low birth weight compared to toddlers with normal birth weight (OR= 0.41; CI 95% 0.23to 0.73; p = 0.001). The incidence of stunting is higher in economic status below the provincial minimum wage < Rp. 3,103,800 compared to economic status > Rp. 3,103,800 (OR = 2.25; CI 95% 1.16 to 4.38; p=0.01). Conclusion: Low economic status has a risk of 2.252 times experiencing stunting. Keywords: Feeding Practice, Low Birth Weight, Stunting Correspondence: Mardhatillah. Faculty of Health Sciences, University of Muhammadiyah Sidenreng Rappang, Indonesia. Jl. Angkatan 45 No. 1, Lotang Salo Sidenreng Rappang, South Sulawesi, Indonesia. Email: mardhatillahds92@gmail.com. Mobile: +6285343350880. Journal of Maternal and Child Health (2022), 07(01): 82-89 https://doi.org/10.26911/thejmch.2022.07.01.09

QTL MAPPING OF BROOMRAPE (OROBANCHE CUMANA WALLR.) RESISTANCE IN SUNFLOWER (HELIANTHUS ANNUUS L.) USING GBS-SNPS

Broomrape is one of the most important biotic stresses causing serious yield reductions in sunflower. Control of this parasitic plant is difficult and physical and chemical strategies are usually insufficient. Therefore, introduction of genetic resistance to broomrape in sunflower is a key breeding goal. Breeding efforts on broomrape resistance have been conducted for decades, however, new broomrape races, such as race F, have emerged and rapidly evolved to be more aggressive and devastating. Although a few quantitative trait loci (QTLs) were identified for race F resistance, none of these loci are suitable for marker assisted selection because of their small phenotypic effects. In the present study, three major QTLs for broomrape race F resistance were identified on LG7, LG11 and LG12 using a high density SNP map constructed with the genotyping by sequencing approach in an intraspecific F2 population. The population consisted of 300 individuals derived from a cross between susceptible Helianthus annuus cv. RHA 436 as the recipient parent and resistant H. annuus cv. H08 M1 as the donor parent. Breeder-friendly SNP-based cleaved amplified polymorphic sequence markers were developed for the QTLs. The QTLs and CAPS markers identified in this study will be valuable molecular genetic tools for sunflower breeding.

Development of Drought Tolerant Rice Breeding Lines of an Elite Indian Rice (Oryza sativa L.) Variety Improved White Ponni through Molecular Breeding

Changes in climatic conditions especially unpredictable drought occurrences are challenging for food security. The present investigation was carried out to improve the grain yield in Improved White Ponni (IWP) rice under reproductive stage drought stress. This variety is well known for its grain quality. Physiological changes, grain yield and related traits under drought were evaluated in the advanced breeding lines of Improved White Ponni X Apo containing qDTY 3.1. The experiment was conducted at the Department of Rice, Centre for Plant Breeding and Genetics, Tamil Nadu Agricultural university, Coimbatore during 2020. Two superior backcross inbred lines of IWP X Apo, donor parent and recipient parent were raised under water stress in rain out shelter as well as in well irrigated conditions in replications. Soil moisture content was reduced to 12.7% in drought field showing the stress severity. Physiological parameters such as photosynthetic rate, transpiration rate, stomatal conductance, chlorophyll content and relative water content, Yield and related traits such as days to fifty percent flowering, productive tillers, spikelet fertility, grain yield and grain weight were recorded in the BILs and parents during flowering stages. Reduction was observed in all these traits under water stress. However, in comparison with IWP (94.6%) which lacks qDTY 3.1, BILs with qDTY 3.1 showed less reduction in grain yield (63%) and other traits. Earliness was also observed in qDTY 3.1 containing BILs under drought stress (BILs - 106 days, IWP-117 days) and controlled conditions (BILs- 83 days, IWP-107 days) when compared to IWP. Grain quality estimates in the BILs showed similarity to IWP. These BILs need to be evaluated further for confirmation of drought tolerance and they are effective resources for utilisation in drought breeding programmes.

Situated Talk: A method for a reflexive encounter with #donorconceived on TikTok

There is a pressing need to facilitate sensitive conversations between people with differing or opposing views. On video-sharing app TikTok, the diverse experiences of donor-conceived people and recipient parents sit uneasily alongside each other, coalescing in hashtags like #donorconceived. This article describes a method ‘Situated Talk’ which uses TikToks to facilitate a reflexive encounter, drawing on three areas of scholarship: media ethnography and elicitation, researcher reflexivity and duoethnography/collaborative autoethnography. We describe how we, as a donor-conceived adult (Giselle) and a queer woman who would need donor sperm to have a child (Clare), employed TikToks from #donorconceived as prompts to facilitate a sensitive conversation and elicit situated insights. We explore three central insights from applying our method: (1) discomfort as a productive tension; (2) unresolved dilemmas; and (3) discovering parallels in experience. Using TikToks as stimuli, ‘Situated Talk’ contributes an innovative method for generating grounded social media insights.

Integrative QTL Identification, Fine Mapping and Candidate Gene Analysis of a Major Locus qLTG3a for Seed Low-Temperature Germinability in Rice

Low-temperature germinability (LTG) is an important agronomic trait that can affect the planting time, planting area, and grain yield of staple crops, such as rice. However, the genetic mechanism of LTG is still unclear. In this study, a multi-parental permanent population with 208 single segment substitution lines (SSSLs) was used to conduct a genetic dissection for LTG across four cropping seasons. LTG was a typical quantitative trait with a high combined broad-sense heritability of 0.71. By comparison with the recipient parent, Huajingxian74, 24 SSSLs were identified as carrying LTG QTLs, which were further merged into integrated QTLs with shorter genetic distances by substitution mapping. Finally, 14 LTG QTLs were mapped on ten chromosomes, including seven positive-effect and seven negative-effect QTLs, with additive effect contributions ranging from 19.2 to 39.9%. qLTG3a, a main-effect and novel QTL, was confirmed by bulk segregant analysis using an F2 segregating population, and five key recombinants were selected to develop F3 populations for progeny testing. Marker-trait association analysis fine mapped qLTG3a to a 332.7-kb physical region between markers M6026 and M6341. Within this interval, 40 annotated genes were revealed, and three genes (Os03g0213300, Os03g0214400, and Os03g0214600) were considered as pivotal candidate genes for qLTG3a based on their sequence variations and expression patterns. Besides low temperature, qLTG3a can also enhance seed germination under standard temperature and osmotic stress. In summary, this study identified some genetic factors regulating LTG and opened a new window for breeding elite direct-seeded rice varieties. It will help reduce the climate risk in the production process of rice, which is of great significance to ensuring food security.

Identification, Analysis, and Confirmation of Seed Storability-Related Loci in Dongxiang Wild Rice (Oryza rufipogon Griff.).

Dongxiang wild rice (Oryza rufipogon Griff.) (DXWR) has strong seed storability and identifying its elite gene resources may facilitate genetic improvements in rice seed storability. In this study, we developed two backcross inbred lines (BILs) populations, with DXWR as a common donor parent and two rice varieties (F6 and R974) as recipient parents. Bulked segregant analysis via whole genome sequencing (BSA-seq) was used to identify seed storability-related loci in the DXWR and F6 population. Two main genomic regions containing 18,550,000–20,870,000 bp on chromosome 4 and 7,860,000–9,780,000 bp on chromosome 9 were identified as candidate loci of DXWR seed storability; these overlapped partially with seed storability-related quantitative trait loci (QTLs) discovered in previous studies, suggesting that these loci may provide important regions for isolating the responsible genes. In total, 448 annotated genes were predicted within the identified regions, of which 274 and 82 had nonsynonymous and frameshift mutations, respectively. We detected extensive metabolic activities and cellular processes during seed storability and confirmed the effects of the seed storability-related candidate loci using four BILs from DXWR and R974. These results may facilitate the cloning of DXWR seed storability-related genes, thereby elucidating rice seed storability and its improvement potential.

Parents’ experiences telling children conceived by gamete and embryo donation about their genetic origins

ObjectiveTo gain an in-depth understanding of parents’ experiences telling children conceived by gamete and embryo donation about their genetic origins.DesignQualitative, descriptive.SettingFamilies’ homes.Patient(s)Gamete or embryo donation recipient parents living in the United States and who told their children, from birth to 16 years, about their genetic origins.Intervention(s)Individual semistructured (n = 12) or dyadic (n = 2) parent interviews.Main Outcome Measure(s)Directed qualitative content analysis.Result(s)Fourteen families that comprised 16 gamete or embryo donation recipient parents and represented 24 donor-conceived children between the ages of 4 months and 16 years participated in the study. Single parents (n = 3) and both parents in most two-parent families (n = 9) led the initial telling conversations. Parents recounted personal short stories using language that was both developmentally and medically appropriate. Multiple strategies, including children’s books, were used by parents to aid them in their telling. The oldest donor-conceived children in each family were first informed of their genetic origins at birth (n = 10 families) or at 6 months (n = 1 family; “practice runs”) or from 3.5 to 12 years (n = 3 families). The telling conversations took place during routine family activities that naturally brought parents and children in close proximity, usually in the home.Conclusion(s)Awareness of the nuances of parents’ telling conversations with their children through the age of 16 years can help guide clinical counseling and the development of tools to aid parents in their telling conversations.

Caregiver burden among adults caring for their Holocaust-survivor parents during the COVID-19 pandemic.

This study aimed to examine the caregiver burden among offspring of Holocaust survivors (OHS) caring for their parents during the COVID-19 pandemic, hypothesizing that caregivers whose parents suffer from posttraumatic stress disorder (PTSD) would report an increased burden. The sample consisted of 109 caregivers with older adult care recipient parents (average caregivers' age = 57.67, SD = 8.49). Caregivers were divided into three groups: 20 OHS who reported that at least one care recipient had PTSD, 60 OHS who reported that their care recipients did not have PTSD, and 29 comparison caregivers (whose care recipients did not undergo the Holocaust). Caregivers completed questionnaires about SARS-CoV-2 exposure, COVID-19 concerns, helping their care recipients, their experiences of caregiver burden, and perceived changes to their caregiver burden during the pandemic. The caregivers also reported PTSD symptoms-in themselves as well as in their care recipients. Relative to comparisons, OHS with parental PTSD reported higher caregiver burden in four aspects: time-dependent burden, developmental burden, physical burden, and social burden. Furthermore, OHS reported a greater perceived increase in caregiver burden during the pandemic than the comparisons. The study findings illuminate the difficulties OHS caregivers, especially those whose care recipients have PTSD, face during the COVID-19 pandemic. This group of caregivers is at risk of experiencing more distress and may need help and support. Further research is needed to determine whether people taking care of their posttraumatic parents following other massive traumatic events also feel a heavier caregiver burden-both in general and specifically during the current pandemic.

Marker-Assisted Pyramiding of Downy Mildew-Resistant Gene Ppa3 and Black Rot-Resistant Gene Xca1bo in Popular Early Cauliflower Variety Pusa Meghna

Cauliflower is an important extensively grown cool season vegetable in India. Black rot and downy mildew are major devastating diseases reducing yield and quality of the crop. To tackle these through host plant resistance, a marker-assisted backcross breeding method was followed to pyramid a black rot-resistant gene (Xca1bo) and a downy mildew-resistant gene (Ppa3) from donors BR-161 and BR-2, respectively, into the background of Pusa Meghna cauliflower cultivar. Marker-assisted backcross breeding was followed up to BC2 generation using SCAR marker ScOPO-04833 and SSR marker BoGMS0624 for black rot and downy mildew resistance genes in foreground selection, respectively. In background selection, at each stage of backcrossing, 47 parental polymorphic SSR markers were used. The graphical genotyping of the five two-gene (Xca1boXca1boPpa3Ppa3) homozygous BC2F2 plants showed an average recovery of 85.44% of the Pusa Meghna genome with highest genome recovery of 91.7%. The genome contribution of donor parents (BR-161 and BR-2) was 8.26 with 6.34% of residual heterozygousity. The backcross derived pyramided lines BC2F2:3-7-16 and BC2F2:3-7-33 showed high resistance to both the diseases and exhibited higher yield and vitamin C content as compared with recipient parent Pusa Meghna. It is, therefore, evident from this study that resistant genes can be introgressed successfully into a Pusa Meghna cultivar without any yield penalty, benefitting farmers with reduced input cost and consumers with chemical residue free produce. Besides, the pyramided lines carrying dominant resistant genes can be exploited in a hybridization programme to develop hybrid(s) in cauliflower.

GW10, a member of P450 subfamily regulates grain size and grain number in rice.

A quantitative trait locus GW10 is located on Chromosome 10 by map-based cloning, which encodes a P450 Subfamily protein. The GW10 regulates grain size and grain number in rice involved in the BR pathway. Grain size and grain number play extremely important roles in rice grain yield. Here, we identify GW10, which encodes a P450 subfamily protein and controls grain size and grain number by using Lemont (tropical japonica) as donor parent and HJX74 (indica) as recipient parent. The GW10 locus was mapped into a 14.6kb region in HJX74 genomic on the long arm of chromosome 10. Lower expression of the gw10 in panicle is contributed to the shorter and narrower rice grain, and the increased number of grains per panicle. In contrast, overexpression of GW10 is contributed to longer and wider rice grain. Furthermore, the higher expression levels of some of the brassinosteroid (BR) biosynthesis and response genes are associated with the NIL-GW10. The sensitivity of the leaf angle to exogenous BR in NIL-GW10 is lower than that in NIL-gw10 and in the KO-GW10, which implied that the GW10 should involve in the brassinosteroid-mediated regulation of rice grain size and grain number.

P–496 Alpha test results: Towards developing a digital prototype intervention to support parents’ disclosure about donor conception in the United States

Abstract Study question The objective of the study was to determine the usability, comprehensibility, and acceptability of a digital, decision-support aid prototype supporting parental disclosure of donor conception. Summary answer: This mixed methods design maximized participant feedback about the digital, decision-support aid prototype yielding rich insight about the prototype while minimizing participant and investigator burden. What is known already Although a paradigm shift is underway to remove the secrecy that has historically shrouded the practice of gamete donation, little is known about best practices that can support parents in disclosing the conceptional origins to their children. To address this gap, we created a decision-support aid prototype to facilitate parental disclosure post-treatment. In doing so, we followed the International Patient Decision Aid Standards Collaboration for developing decision-support aids, which recommends that Alpha testing (i.e., usability, comprehensibility, and acceptability) be completed to improve the quality of newly created decision-support interventions prior to Beta (i.e., real world) testing. Study design, size, duration A mixed-methods, triangulation design was used. Participants/materials, setting, methods Sixteen participants were purposefully selected based on desired characteristics and the needs of the study. Participants were asked to: (1) follow investigator prepared instructions for accessing the digital, decision-support aid; (2) complete a quantitative rating form about each slide within the decision-support aid prototype; and (3) participate in a qualitative, cognitive interview or focus group. Descriptive statistics and qualitative content analysis guided the iterative analysis. Main results and the role of chance The sample was composed of 10 parents that used donated sperm (n = 3), oocytes (n = 4), or embryos (n = 2) to conceive children and 8 clinicians; 2 participants were both donor recipient parents and clinicians. The interviews (n = 14) and one focus group (2 participants) ranged in length from 25 to 70 minutes (M = 47 minutes). Usability: Participants suggested refining the instructions for accessing the decision-support aid and upgrading the technology used to deliver the content. Common concerns were the inconsistent volume of the audio recordings and a need for higher quality images. Comprehensibility: Feedback obtained from the participants’ rating forms and in the interviews and focus group were consistently high about the ability to understand the content and the scope of the information presented. Acceptability: Participants noted the aid would resonate with parents. They recommended shortening the length of the aid, changing specific wording, modifying some of the video content, refining specific content for individual slides and the four modules. Unintended recommendations about how the aid might be used to provide clinician education or in international research were also reported. Limitations, reasons for caution Alpha testing is not designed to obtain all possible technological or content issues. Rather, it is a useful and recommended step in intervention development to mitigate existing technological bugs and key content issues prior to implementation of Beta testing of a decision-support aid. Wider implications of the findings: Other investigators that develop digital decision-support aids may consider the use of both quantitative and qualitative data collection methods during Alpha testing to refine digital interventions efficiently. The use of mixed methods not only captures rich and insightful feedback but also minimizes the burden on participants and investigators. Trial registration number Not applicable