Traits In Breeding Research Articles

Genome-wide association studies of egg production traits by whole genome sequencing of Laiwu Black chicken

Compared to high-yield commercial laying hens, Chinese indigenous chicken breeds have poor egg laying capacity due to the lack of intensive selection. However, as these breeds have not undergone systematic selection, it is possible that there is a greater abundance of genetic variations related to egg laying traits. In this study, we assessed 5 egg number (EN) traits at different stages of the egg-laying period: EN1 (from the first egg to 23 wk), EN2 (from 23 to 35 wk), EN3 (from 35 to 48 wk), EN4 (from the first egg to 35 wk), and EN5 (from the first egg to 48 wk). To investigate the molecular mechanisms underlying egg number traits in a Chinese local chicken breed, we conducted a genome-wide association study (GWAS) using data from whole-genome sequencing (WGS) of 399 Laiwu Black chickens. We obtained a total of 3.01 Tb of raw data with an average depth of 7.07 × per individual. A total of 86 genome-wide suggestive or significant single-nucleotide polymorphisms (SNP) contained within a set of 45 corresponding candidate genes were identified and found to be associated with stages EN1-EN5. The genes vitellogenin 2 (VTG2), lipase maturation factor 1 (LMF1), calcium voltage-gated channel auxiliary subunit alpha2delta 3 (CACNA2D3), poly(A) binding protein cytoplasmic 1 (PABPC1), programmed cell death 11 (PDCD11) and family with sequence similarity 213 member A (FAM213A) can be considered as the candidate genes associated with egg number traits, due to their reported association with animal reproduction traits. Noteworthy, results suggests that VTG2 and PDCD11 are not only involved in the regulation of EN3, but also in the regulation of EN5, implies that VTG2 and PDCD11 have a significant influence on egg production traits. Our study offers valuable genomic insights into the molecular genetic mechanisms that govern egg number traits in a Chinese indigenous egg-laying chicken breed. These findings have the potential to enhance the egg-laying performance of chickens.

Investigation of cosmopolitan and local Italian beef cattle breeds uncover common patterns of heterozygosity

The analysis of livestock heterozygosity is less common compared to the study of homozygous patterns. Heterozygous-Rich Regions (HRRs) may harbor significant loci for functional traits such as immune response, survival rate, and fertility. For this reason, this study was conducted to investigate and characterize the heterozygosity patterns of four beef cattle breeds, which included two cosmopolitan breeds (Limousine and Charolaise) and two local breeds (Sarda and Sardo Bruna). Our analysis identified regions with a high degree of heterozygosity using a consecutive runs approach, the Tajima D test, nucleotide diversity estimation, and Hardy Weinberg equilibrium test. These regions exhibited recurrent heterozygosity peaks and were consistently found on specific chromosomes across all breeds, specifically autosomes 15, 16, 20, and 23. The cosmopolitan and Sardo Bruna breeds also displayed peaks on autosomes 2 and 21, respectively. Thirty-five top runs shared by more than 25% of the populations were identified. These genomic fragments encompassed 18 genes, two of which are directly linked to male fertility, while four are associated with lactation. Two other genes play roles in survival and immune response. Our study also detected a region related to growth and carcass traits in Limousine breed. Our analysis of heterozygosity-rich regions revealed particular segments of the cattle genome linked to various functional traits. It appears that balancing selection is occurring in specific regions within the four examined breeds, and unexpectedly, they are common across cosmopolitan and local breeds. The genes identified hold potential for applications in breeding programs and conservation studies to investigate the phenotypes associated with these heterozygous genotypes. In addition, Tajima D test, Nucleotide diversity, and Hardy Weinberg equilibrium test confirmed the presence of heterozygous fragments found with Heterozygous-Rich Regions analysis.

Identification of some genetic markers as productive and reproductive traits in Ukrainian dairy cattle breeding

A Selection based on DNA markers is a breeding technique grounded in the genomic selection value of animals. The aim of the research is to study the genotypic profile of cows of different breeds in Ukrainian breeding in relation to the genes LEP, CSN3, TG5, BLG, and Pit-1 and to identify the probability of using them as markers for reproductive traits in cows. During the study, the Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method was used to analyze the genes and determine their polymorphic characteristics. The obtained data indicated that the same gene variants have varying effects in the studied breeds due to their diverse influences on the genomic background. Specifically, the homozygous state of leptin genes (LEPCC) and pituitary-specific transcription factor (PIT-1BB) was observed to impact the reproductive characteristics of cows in the evaluated breeds. Meanwhile, for the genes casein (CSN3AB), thyroglobulin (TG5CT), and beta-lactoglobulin (BLGAВ), the heterozygous state of alleles was found to influence the key reproductive traits of dairy cattle of Holstein origin. The polymorphism of the genes CSN3, βLG, TG, PIT-1, and LEP indicated the presence of genetic potential for the reproductive function of cows and can be utilized as molecular markers in selective breeding, providing significant progress in improving not only the traits of dairy cattle productivity but also reproductive function. Therefore, in the implementation of selective breeding work, it is advisable to consider genotyping for the genes CSN3, βLG, TG, PIT-1, and LEP as an additional criterion for the selection of animals to enhance both their milk and reproductive characteristics.

Genomic dissection of productivity, lodging, and morpho‐physiological traits in Eragrostis tef under contrasting water availabilities

Societal Impact StatementUnderutilized species (also known as orphan crops) present opportunities to increase crop diversity and food security. Such crops lack modern genetic tools and knowledge to facilitate efficient modern breeding approaches. A wide collection of tef (Eragrostis tef (Zucc.) Trotter) genotypes was used to identify genomic regions associated with productivity, lodging, and morpho‐physiological traits under contrasting water availabilities. The obtained results are expected to enhance modern breeding and improve tef productivity under traditional and modern cropping systems, thus improving farmers' livelihood and food security.Summary Tef (E. tef (Zucc.) Trotter) is an allotetraploid (2n = 4x = 40) C4 cereal crop, endemic to Ethiopia and mainly cultivated in the Horn of Africa. Tef is characterized by high grain and feed nutritional qualities and resilience to abiotic and biotic stresses; thus, it holds great potential to sustain food and nutrition security in Africa and other parts of the world. The objective of this study was to identify genomic regions associated with responses to contrasting water regimes, as a basis for future improvement. A tef diversity panel was genotyped with 28,837 single nucleotide polymorphisms (SNPs) and phenotyped for productivity, lodging, and morpho‐physiological traits along two seasons (2020 and 2021) under well‐watered and water‐limited treatments. A genome‐wide association study was performed to identify genomic regions associated with key traits for tef breeding. A total of 107 SNPs were associated with one or more of the studied traits, resulting in 138 marker–trait associations (MTAs) detected under both water treatments. Of these, 22 SNPs were associated with more than one trait, showing either multiple trait (pleiotropic) or multiple environment associations or both. A particularly strong association was found between grain yield, lodging, and time to heading. These findings open new avenues to further research on the genetic basis and physiological mechanisms underlying major traits in tef, as well as to marker‐assisted breeding of drought‐resilient tef cultivars.

Morphometric characteristics as an indicator of the breeding process in carp

The study of the variability of exterior indicators in two-year-olds of three different strains of carp: the natural population of the Volga carp, the breed group of the Zagorsky carp and the butterfly carp breed. The research was carried out on the basis of the pond base of the experimental breeding farm of the VNIIPRH. It is shown that the introduction of the index of the relative size of the head to the total body surface into the analysis of a new breeding trait determines the significant discrepancy between the groups of the Volga carp and carp in the complex of morphotype features. It was found that the Volga carp is the most distant from the butterfly carp (the distance of the Mahalanobis is 13.18), as well as from the breed group of the Zagorsky carp (8,66). The breed groups of carp are located closer to each other (4.18). The greatest contribution to the separation of the studied groups of cyprinid fish is made by 7 morphotype features — body length, indices of pectoventral and antedorsal distance, length of snout, tail and dorsal fin, the ratio of head area to body area of fish. The relative head sizes of the carp breed groups are significantly higher than those of the Volga carp, which has not been selected in fish aquaculture. Thus, the head size of the Volga carp occupies 15.06%, and that of the carp after 7 generations of breeding — 15.93–16.82%. The Volga carp is characterized by higher values of body length and low values of relative head size, high back, fatness coefficient and body girth. It is shown that the relative size of the head can serve as an indicator of the difference in the breed groups of carp. An increase in the ratio of the head area to the surface of the entire fish is observed in the series: Volga carp — Zagorsky carp — butterfly. It is proposed to use this indicator as an additional characteristic of the breeding process and domestication of cyprinid fish.

Exploring Breed-Specific Milk Coagulation in Spanish Dairy Sheep: A Canonical Correlation Approach.

The transformation of milk into cheese largely depends on the technological properties of the raw material, with breed being a crucial factor that influences both the composition and coagulation properties of the milk used for cheesemaking. This study uses canonical correlation analysis to explore the relationships between physicochemical traits and coagulation properties in milk from various Spanish breeds, aiming to identify both common and breed-specific patterns that impact milk technological aptitude. A total of 832 milk samples from Manchega, Assaf, Merino de Grazalema, and Merino de Los Pedroches breeds were analyzed. The milk characteristics investigated included pH, composition (fat, protein, lactose, total solids), and coagulation properties (curd firmness-A60, rennet clotting time-RCT, curd firming time-k20, and individual laboratory curd yield-ILCY). The results reveal a shared correlation structure across breeds and unique covariation patterns in some breeds that deviate from the general trend. While Assaf and Merino de Los Pedroches follow the common correlation pattern, Manchega and Merino de Grazalema exhibit distinct patterns. This research underscores the need for in-depth study and suggests that the dairy industry could benefit from shifting from the traditional focus on maximizing fat and protein for higher curd yields to considering technological traits for selective breeding.

Development of Genome-Wide Intron Length Polymorphism (ILP) Markers in Tea Plant (Camellia sinensis) and Related Applications for Genetics Research.

The market value of tea is largely dependent on the tea species and cultivar. Therefore, it is important to develop efficient molecular markers covering the entire tea genome that can be used for the identification of tea varieties, marker-assisted breeding, and mapping important quantitative trait loci for beneficial traits. In this study, genome-wide molecular markers based on intron length polymorphism (ILP) were developed for tea trees. A total of 479, 1393, and 1342 tea ILP markers were identified using the PCR method in silico from the 'Shuchazao' scaffold genome, the chromosome-level genome of 'Longjing 43', and the ancient tea DASZ chromosome-level genome, respectively. A total of 230 tea ILP markers were used to amplify six tea tree species. Among these, 213 pairs of primers successfully characterize products in all six species, with 112 primer pairs exhibiting polymorphism. The polymorphism rate of primer pairs increased with the improvement in reference genome assembly quality level. The cross-species transferability analysis of 35 primer pairs of tea ILP markers showed an average amplification rate of 85.17% through 11 species in 6 families, with high transferability in Camellia reticulata and tobacco. We also used 40 pairs of tea ILP primers to evaluate the genetic diversity and population structure of C. tetracocca with 176 plants from Puan County, Guizhou Province, China. These genome-wide markers will be a valuable resource for genetic diversity analysis, marker-assisted breeding, and variety identification in tea, providing important information for the tea industry.

Evidence of subpopulation diversification and traces of introgression within Canarian camel breed zoometric standard: scope and opportunities for selection

Extant diversity for phenotypic traits is an essential criterion to be considered when ordering priorities for conservation and improvement of animal genetic resources. Concretely, the characterisation of the distinctive body morphometry of a particular group of animals can aid in the design of selective breeding programs, given the strong correlation between body morphology and productive function. The present research aims to characterise an endangered autochthonous camel breed (Canarian camel), mainly relegated to leisure riding, for its body morphology, with a double objective: to explore the phenotypic diversity and structure of the breed for zoometric traits and assess the zoometric profile of this genetic resource that supports its differentiation from other camel breeds. Overall, the results highlight the existence of a high degree of diversity, which may be linked to genetic factors for zoometric traits in an endangered autochthonous breed with traditional in situ breeding schemes, which predicts the success of the implementation of genetic improvement schemes for such functional characteristics. This phenotypic diversity in body morphology could also be a tool for the evaluation of new functional niches within the efforts of functional valorisation of this camel breed for its sustainable conservation. Body morphology traits in the studied camel breed are significantly influenced by sex, physiological status and coat colour.

The Height Pole: Measuring plot height using a single‐point LiDAR sensor

AbstractPlant canopy height is an essential trait for phenomics and plant breeding. Despite its importance, height is still largely measured by manual means with a ruler and notepad. Here, we present the Height Pole, a novel single‐point LiDAR (SPL)‐based instrument to measure and record plant and canopy height in the field quickly, reliably, and accurately. An SPL was mounted on the top of a pole and aimed downwards at an adjustable paddle that was positioned at the desired height. A custom app, written for Android OS, saved the plant height data from the SPL to a tablet. The Height Pole was tested against a ruler in the lab, in a field trial setting, and by multiple operators. Indoor and outdoor testing found no significant differences between a ruler and the Height Pole measurements. A test with five operators revealed that measuring, recording, transcribing, and digitizing were on average 20 s per plot slower with a ruler than with the Height Pole. The Height Pole required only one operator to measure and record data, reduced operator fatigue, and by directly writing the data to a .CSV file eliminated transcription errors. These improvements make it easier to collect crop height data on large experiments rapidly and accurately with low input costs.

Crop Landraces and Indigenous Varieties: A Valuable Source of Genes for Plant Breeding.

Landraces and indigenous varieties comprise valuable sources of crop species diversity. Their utilization in plant breeding may lead to increased yield and enhanced quality traits, as well as resilience to various abiotic and biotic stresses. Recently, new approaches based on the rapid advancement of genomic technologies such as deciphering of pangenomes, multi-omics tools, marker-assisted selection (MAS), genome-wide association studies (GWAS), and CRISPR/Cas9 gene editing greatly facilitated the exploitation of landraces in modern plant breeding. In this paper, we present a comprehensive overview of the implementation of new genomic technologies and highlight their importance in pinpointing the genetic basis of desirable traits in landraces and indigenous varieties of annual, perennial herbaceous, and woody crop species cultivated in the Mediterranean region. The need for further employment of advanced -omic technologies to unravel the full potential of landraces and indigenous varieties underutilized genetic diversity is also indicated. Ultimately, the large amount of genomic data emerging from the investigation of landraces and indigenous varieties reveals their potential as a source of valuable genes and traits for breeding. The role of landraces and indigenous varieties in mitigating the ongoing risks posed by climate change in agriculture and food security is also highlighted.

Associations Between BLG, CSN3, DGAT1, GH, PIT1, and PRL Gene Polymorphisms and Milk Production Traits in Holstein Dairy Cows: A Meta-Analysis.

The current meta-analysis was employed to combine the results of multiple studies into a single estimate related to B-LG, CSN3, DGAT1, PRL, GH, and PIT1 gene polymorphisms and their effects on milk production traits. The purpose of this meta-analysis was to investigateassociations between B-LG, CSN3, DGAT1, GH, PIT1, and PRLgene polymorphisms with milk production traits in Holstein dairy cows. An extensive search was done from 2002 to 2022year. Statistical analyses were performed by using Stata 11.2 software. Genetic models viz codominant (AA vs. AB, AA vs. BB, and AB vs. BB), dominant (AA + AB vs. BB), recessive (AA vs. AB + BB), and completely over-dominant (AA + BB vs. AB) were applied. The results of meta-analysis of association between B-LG genotypes with milk yield where found a significant (P < 0.05) and with fat and protein contents (P < 0.01). In CSN3 polymorphisms of A/A and A/B genotypes had a significant effect on fat yield (P < 0.05) and protein content (P < 0.01). DGAT1 polymorphisms had a significant effect on milk yield, fat yield, protein yield (P < 0.05), with fat and protein contents showed high effect (P < 0.01). No significant association was detected between GH and milk traits (P > 0.05). PIT1 genotype polymorphisms had a significant effect on milk yield (P < 0.05) and protein content (P < 0.01). PRL genotype polymorphisms were significantly associated with milk yield (P < 0.05), fat content and protein yield (P < 0.01). The B-LG, DGAT1,CSN3 and PRL gene polymorphisms could be utilized as good markers to improve milk production traits in the Holstein cattle breed.

Feed efficiency of dairy cattle as genetic trait

This review article is devoted to the use of feed efficiency traits in dairy cattle breeding. An efficient cow is defined as the one that produces the same amount of milk and milk solids while consuming less feed and remaining healthy and fertile; thus, allowing to reduce costs without decrease in production. Improving feed efficiency is economically important due to the increasing price of fodder. Feed efficiency is a genetically complex trait that can be described as units of product output (e.g., milk yield) per unit of feed input. Nowadays genetic evaluation of dairy cattle for feed efficiency is routinely conducted in several countries, including Australia, USA, Canada, Netherlands, Denmark, Sweden, Finland, Norway and United Kingdom. Different countries use different measures of feed efficiency of dairy cows. The main feed efficiency traits are dry matter intake, gross feed efficiency, residual feed intake, energy balance and feed saved. Genome-wide association studies demonstrated that feed efficiency in polygenic trait. Nevertheless, several genes with large effects on feed efficiency were identified. Estimates of heritability of these traits vary from 0.07 to 0.49 and show the presence of considerable genetic variation of these traits and therefore, the possibility of their genetic improvement under the conditions of inclusion in breeding programs. Changes in diet and rumen microbiome substantially impact feed efficiency of dairy cows. Feed efficiency is related to methane emissions and excess nitrogen excretion. Genetic improvement of feed efficiency requires recording of individual data on feed intake in cows. Such data are limited. Two options exist to solve this problem: use of indirect predictors and genomic prediction. Accuracy of genomic prediction varies from 0.21 to 0.61 across countries. International cooperative pro­jects such as Efficient Dairy Genome Project in Canada were launched to establish large databases and to increase accuracy of feed efficiency traits genomic prediction. Future directions of research are the use of novel technologies: mid-infrared spectroscopy, artificial intelligence, holo-omics.

Enhancing the genomic prediction accuracy of swine agricultural economic traits using an expanded one-hot encoding in CNN models1

Deep learning (DL) methods like Multilayer Perceptrons (MLPs) and Convolutional Neural Networks (CNNs) have been applied to predict the complex traits in animal and plant breeding. However, improving the genomic prediction accuracy still presents significant challenges. In this study, we applied CNNs to predict swine traits using previously published data. Specifically, we extensively evaluated the CNN model’s performance by employing various sets of Single Nucleotide Polymorphisms (SNPs) and concluded that the CNN model achieved optimal performance when utilizing SNP sets comprising 1,000 SNPs. Furthermore, we adopted a novel approach using the one-hot encoding method that transforms the 16 different genotypes into sets of eight binary variables. This innovative encoding method significantly enhanced the CNN’s prediction accuracy for swine traits, outperforming the traditional one-hot encoding techniques. Our findings suggest that the expanded one-hot encode method can improve the accuracy of DL methods in the genomic prediction of swine agricultural economic traits. This discovery has significant implications for swine breeding programs, where genomic prediction is pivotal in improving breeding strategies. Furthermore, future research endeavors can explore additional enhancements to DL methods by incorporating advanced data pre-processing techniques.

A genomic toolkit for winged bean Psophocarpus tetragonolobus

A sustainable supply of plant protein is critical for future generations and needs to be achieved while reducing green house gas emissions from agriculture and increasing agricultural resilience in the face of climate volatility. Agricultural diversification with more nutrient-rich and stress tolerant crops could provide the solution. However, this is often hampered by the limited availability of genomic resources and the lack of understanding of the genetic structure of breeding germplasm and the inheritance of important traits. One such crop with potential is winged bean (Psophocarpus tetragonolobus), a high seed protein tropical legume which has been termed ‘the soybean for the tropics’. Here, we present a chromosome level winged bean genome assembly, an investigation of the genetic diversity of 130 worldwide accessions, together with two linked genetic maps and a trait QTL analysis (and expression studies) for regions of the genome with desirable ideotype traits for breeding, namely architecture, protein content and phytonutrients.

A 5.2-kb insertion in the coding sequence of PavSCPL, a serine carboxypeptidase-like enhances fruit firmness in Prunus avium.

Fruit firmness is an important trait in sweet cherry breeding because it directly positively influences fruit transportability, storage and shelf life. However, the underlying genes responsible and the molecular mechanisms that control fruit firmness remain unknown. In this study, we identified a candidate gene, PavSCPL, encoding a serine carboxypeptidase-like protein with natural allelic variation, that controls fruit firmness in sweet cherry using map-based cloning and functionally characterized PavSCPL during sweet cherry fruit softening. Genetic analysis revealed that fruit firmness in the 'Rainier' × 'Summit' F1 population was controlled by a single dominant gene. Bulked segregant analysis combined with fine mapping narrowed the candidate gene to a 473-kb region (7418778-7 891 914 bp) on chromosome 6 which included 72 genes. The candidate gene PavSCPL, and a null allele harbouring a 5244-bp insertion in the second exon that completely inactivated PavSCPL expression and resulted in the extra-hard-flesh phenotype, were identified by RNA-sequencing analysis and gene cloning. Quantitative RT-PCR analysis revealed that the PavSCPL expression level was increased with fruit softening. Virus-induced gene silencing of PavSCPL enhanced fruit firmness and suppressed the activities of certain pectin-degrading enzymes in the fruit. In addition, we developed functional molecular markers for PavSCPL and the Pavscpl5.2-k allele that co-segregated with the fruit firmness trait. Overall, this research identified a crucial functional gene for fruit firmness. The results provide insights into the genetic control and molecular mechanism of the fruit firmness trait and present useful molecular markers for molecular-assisted breeding for fruit firmness in sweet cherry.

Integrated transcriptomic analysis on chicken ovary reveals CYP21A1 affects follicle granulosa cell development and steroid hormone synthesis

Egg production is an economically important trait in poultry breeding and production. Follicular development was regulated by several hormones released and genes expressed in the granulosa cells, impacting the egg production and fecundity of hens. However, the molecular functions of these candidate genes that modulate these processes remain largely unknown. In the present study, bioinformatics analyses were performed to identify the candidate genes related to egg production in the ovarian tissue of White Leghorns with high egg production and Beijing You chicken with low egg production during sexual maturity and peak laying periods. The ovarian granulosa cells were used to assess the function of CYP21A1 by transfecting with CYP21A1-specific small interfering RNAs (siRNAs) and overexpression plasmids. We identified 514 differentially expressed genes (|Log2(fold change) | >1, P <0.05) between the 2 chicken breeds in both laying periods. Among these genes, CYP21A1, which is involved in the steroid hormone biosynthesis pathway was consistently upregulated in White Leghorns. Weighted gene co-expression network analysis (WGCNA) further suggested that CYP21A1 was a hub gene, which could positively respond to treatment with follicle stimulation hormone (FSH), affecting egg production. The interference of CYP21A1 significantly inhibited cell proliferation and promoted cell apoptosis. Overexpression of CYP21A1 promotes cell proliferation and inhibits cell apoptosis. Furthermore, the interference with CYP21A1 significantly downregulated the expression of STAR, CYP11A1, HSD3B1, and FSHR and also decreased the synthesis of progesterone (P4) and estradiol (E2) in granulosa cells. Overexpression of CYP21A1 increased the synthesis of P4 and estradiol E2 and the expression of steroid hormone synthesis-related genes in granulosa cells. Our findings provide new evidence for the biological role of CYP21A1 on granulosa cell proliferation, apoptosis, and steroid hormone synthesis, which lays the theoretical basis for improving egg production.

Production and cultivation dynamics of millets in India

AbstractMillets gained a great attention at the global level in 2023 which is celebrated as the “International Year of Millets” to create awareness to eventually promote consumption and production. An attempt is made here to understand the cultivation and production dynamics of millets as influenced by their demand and supply. We also assess challenges and emerging opportunities to make millets more productive, competitive, and relevant to future farming. Millets registered a 60% decline in area and a 200% rise in productivity, but production has remained the same during the last seven decades. The demand of millets decreased as food due to greater incentives (purchasing grain at a pre‐determined price) and policies (distribution of grains to the public at a subsidized rate) in favor of wheat and rice. Millets would play a greater role in future agriculture due to challenges posed by climate change, limited water supply, and reduced agro‐biodiversity. This would need a much greater intensity of investment in millet research and adequate support as extended to wheat and rice. Increased emphasis on their genetic improvement and agronomic management is required to develop cultivars, using new tools and technologies, with high production potential and adequate environmental adaptation to make millets competitive with other crops. Mainstreaming the nutritional traits in millet breeding is also critically important to develop high‐yielding cultivars with improved grain quality traits. Promoting millet consumption would remain the key issue for increasing their demand as food, feed, and industrial raw materials through policies and awareness programs. Strengthening of value chain will help in diversifying agri‐food production system and creating an ecosystem for millet promotion.

Exploring silique number in Brassica napus L.: Genetic and molecular advances for improving yield.

Silique number is a crucial yield-related trait for the genetic enhancement of rapeseed (Brassica napus L.). The intricate molecular process governing the regulation of silique number involves various factors. Despite advancements in understanding the mechanisms regulating silique number in Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa), the molecular processes involved in controlling silique number in rapeseed remain largely unexplored. In this review, we identify candidate genes and review the roles of genes and environmental factors in regulating rapeseed silique number. We use genetic regulatory networks for silique number in Arabidopsis and grain number in rice to uncover possible regulatory pathways and molecular mechanisms involved in regulating genes associated with rapeseed silique number. A better understanding of the genetic network regulating silique number in rapeseed will provide a theoretical basis for the genetic improvement of this trait and genetic resources for the molecular breeding of high-yielding rapeseed.

Morphological Analyses and QTL Mapping of Mottled Leaf in Zucchini (Cucurbita pepo L.).

The mottled leaf is one of the agronomic traits of zucchini and can be applied as a marker trait in aggregation breeding. However, the genetic mechanism responsible for mottled leaf has yet to be elucidated. In the present study, we used two inbred lines (line '19': silver mottled leaf; line '113': normal leaf) as parents for the physiological and genetic analysis of mottled leaf. The synthesis and net photosynthetic rate of chlorophyll were not significantly affected in the mottled areas of leaves. However, we detected a large space between the palisade parenchyma in the leaf mottle area of line '19', which may have caused the mottled leaf phenotype. Light also plays an important role in the formation of mottled leaf, and receiving light during the early stages of leaf development is a necessary factor. Genetic analysis has previously demonstrated that mottled leaf is a quantitative trait that is controlled by multiple genes. Based on the strategy of quantitative trait locus sequencing (QTL-seq), two QTLs were identified on chromosomes 1 and 17, named CpML1.1 and CpML17.1, respectively. Two major loci were identified using R/qtl software version 1.66 under greenhouse conditions in April 2019 (2019A) and April 2020 (2020A) and under open cultivation conditions in May 2020 (2020M). The major QTL, CpML1.1, was located in a 925.2-kb interval on chromosome 1 and explained 10.51%-24.15% of the phenotypic variation. The CpML17.1 was located in a 719.7-kb interval on chromosome 17 and explained 16.25%-38.68% of the phenotypic variation. Based on gene annotation, gene sequence alignment, and qRT-PCR analysis, the Cp4.1LG01g23790 at the CpML1.1 locus encoding a protein of the TPX2 family (target protein of Xklp2) may be a candidate gene for mottled leaf in zucchini. Our findings may provide a theoretical basis for the formation of mottled leaf and provide a foundation for the fine mapping of genes associated with mottled leaf. Molecular markers closely linked to mottled leaf can be used in molecular-assisted selection for the zucchini mottled leaf breeding.

EFFECT OF ECOLOGICAL CONDITIONS ON DESI AND FAYOUMI CHICKEN TRAITS AT DISTRICT KASHMORE, SINDH-PAKISTAN

The present study was undertaken to evaluate the different body organs measurement and multiple phenotypic traits of desi and fayoumi selected chicken breeds under free range and intensive management conditions during, 2021. Host birds were collected from local peoples and hatcheries of district Kashmore and brought through intensive care management system in Animal Husbandry, Department of Zoology, Shah Abdul Latif University Khairpur Mirs. Both chicken male and female populations were reared separately in the same ecology and F1 generation chickens were obtained. The feeding and rearing procedures were followed by NRC and ISA recommended guidelines. The average values of phenotypic traits like neck length of desi and fayoumi males measured in cm (20.4±1.9), (16.5±1.4) body height (43.4±3.2), (33.7±3.2) shank length (12.5±0.82) (8.3±0.72) beak length (3.6±0.21) (2.7±0.16) and wings span (23.7±1.6) (18.3±1.5) in intensive conditions. While as, in the free range conditions the neck length of desi and fayoumi males was recorded in cm (18.7±1.6) (16.4±1.3) body height (38.7±3.2) (34.6±3.1), shank length (10.3±0.97) (9.4±0.94), length of beak (3.3±0.24) (2.7±0.18), and wing span (20.4±1.5) (18.5±1.4), in both chicken breeds. The different phenotype traits of desi and fayoumi chicken breeds viz., the color of eyes, comb, plumage, feather, barbell, mumps, and beak colors percentage were found with variation in intensive and free range conditions. Concludingly, desi chickens were found with larger body parts with dark color variants. The present study suggests, more work should be carried on other characteristics to enhance poultry quality and quantity in future endeavors.