Pedigree Research Articles

Imputation to whole-genome sequence and its use in genome-wide association studies for pork colour traits in crossbred and purebred pigs.

Imputed whole-genome sequence (WGS) has been proposed to improve genome-wide association studies (GWAS), since all causative mutations responsible for phenotypic variation are expected to be present in the data. This approach was applied on a large number of purebred (PB) and crossbred (CB) pigs for 18 pork color traits to evaluate the impact of using imputed WGS relative to medium-density marker panels. The traits included Minolta A*, B*, and L* for fat (FCOL), quadriceps femoris muscle (QFCOL), thawed loin muscle (TMCOL), fresh ham gluteus medius (GMCOL), ham iliopsoas muscle (ICOL), and longissimus dorsi muscle on the fresh loin (FMCOL). Sequence variants were imputed from a medium-density marker panel (61K for CBs and 50K for PBs) in all genotyped pigs using BeagleV5.0. We obtained high imputation accuracy (average of 0.97 for PBs and 0.91 for CBs). GWAS were conducted for three datasets: 954 CBs and 891 PBs, and the combined CBs and PBs. For most traits, no significant associations were detected, regardless of panel density or population type. However, quantitative trait loci (QTL) regions were only found for a few traits including TMCOL Minolta A* and GMCOL Minolta B* (CBs), FMCOL Minolta B*, FMCOL Minolta L*, and ICOL Minolta B* (PBs) and FMCOL Minolta A*, FMCOL Minolta B*, GMCOL Minolta B*, and ICOL Minolta B* (Combined dataset). More QTL regions were identified with WGS (n = 58) relative to medium-density marker panels (n = 22). Most of the QTL were linked to previously reported QTLs or candidate genes that have been previously reported to be associated with meat quality, pH and pork color; e.g., VIL1, PRKAG3, TTLL4, and SLC11A1, USP37. CTDSP1 gene on SSC15 has not been previously associated with meat color traits in pigs. The findings suggest any added value of WGS was only for detecting novel QTL regions when the sample size is sufficiently large as with the Combined dataset in this study. The percentage of phenotypic variance explained by the most significant SNPs also increased with WGS compared with medium-density panels. The results provide additional insights into identification of a number of candidate regions and genes for pork color traits in different pig populations.

The use of amino acids as anti-browning agents in rice parboiling: Effects on quality attributes of three South American genotypes

The parboiling process improves the physical and nutritional quality of rice, but promotes browning, mainly due to the occurrence of the Maillard reaction (MR). Five different amino acids (glycine, methionine, glutamine, sodium glutamate, and aspartate) were studied as limiting agents of the MR in the parboiling process of two pure lines (Guri Inta CL and Irga 424 RI) and a hybrid (Titan CL) genotype. Samples were hydrated under two concentrations of those amino acids (1.5% and 3.0%) during the first step of parboiling. Methionine, glutamine, and aspartate were less effective in preventing the browning of parboiled rice. Glycine (26.63–28.48 GBZ) and sodium glutamate (26.88–28.12 GBZ) were able to provide lighter color to parboiled rice in comparison to control treatment (23.68 GBZ). Parboiled rice treated with amino acids had a lower degree of gelatinization when compared to the control treatment. The extent of gelatinization in parboiled rice produced by using amino acids as anti-browning agents may vary as a function of the applied amino acid molecule and its concentration as well as a result of the characteristics of the selected rice genotype. The percentage of broken grains only increased for the Irga 424 RI genotype, which exhibited shorter cooking time due to the greater ability of the grains to soften during cooking.

Congenital malformations in brachycephalic dogs: A retrospective study.

The popularity of brachycephalic dogs has increased in recent years due to their docile temperament and peculiar features. The historical inbreeding and consequent lack of genetic diversity involved in the development of these breeds led to an increase in the manifestation of deleterious genes that may lead to malformations. In addition, there are serious health issues intrinsic to the conformation, mainly attributed to these extreme characteristics. Therefore, this retrospective study aimed to observe the frequency of malformations in brachycephalic dogs compared to the pure and mixed breeds (MB). The medical records of pregnant bitches admitted at the Service of Obstetrics and Animal Reproduction (SORA) from January 2017 to December 2021 were retrieved from the hospital's computer system and analyzed one by one. Seven hundred sixty-eight neonates born from 168 litters were included in this study. Of these litters, 72.6% (122/168) were brachycephalic. Malformations were found in 52 puppies, with an incidence of 6.77% (52/768). Of the 32 litters that produced malformed puppies, 28 were brachycephalic (87.5%). In total, 23 types of malformations were registered, the most common being cleft palate (1.30%) and anasarca (1.17%). Ten of the puppies (10/52; 19.23%) presented two or more associated malformations. Bitches above 7 years were more prone to present malformed puppies in their litters. Brachycephalic breeds were 3.03 times more likely to present malformed neonates when compared to other breeds; the odds ratio increased to 5.07 when modern brachycephalic was compared to ancestral brachycephalic. Regarding the mode of delivery, elective cesarean sections accounted for 66.6% of births while 19.64% were eutocic vaginal deliveries, and 13.69% were dystocic. The presence of malformed puppies in a litter causes suffering for the owner, the bitch and for the puppy itself, therefore, the veterinarian plays a key role in this scenario. Knowledge about congenital abnormalities, their causes, diagnosis, and approach is essential to reduce the incidence of malformations and improve the quality of life of these animals.

Improved Formulation for Sliding Friction Torque of Deep Groove Ball Bearings

This paper presents an improved formulation, to estimate the sliding friction torque of deep groove ball bearings (DGBBs). Running torque of rolling element bearings, is directly associated with heat generation in rotating machines. Among the components of running torque, sliding friction is a major friction source in ball bearings. For DGBBs, sliding friction is dominated by spinning and differential sliding between balls and races. This paper addresses the sliding friction torque components of DGBBs: Spinning friction, differential sliding friction due to the ball rotation, and differential sliding friction due to the ball orbital motion. An efficient and accurate computational method is proposed for the individual sliding friction sources, based on pure rolling lines in the elliptical contact area between the balls and races. The proposed method applies an updating algorithm, for estimating more accurate information about the pure rolling lines. The proposed method was validated in terms of comparison with other methods, and with the empirical formulae provided by a bearing manufacturer. Simulations were also conducted to investigate the impacts of important parameters on the sliding friction torque in DGBBs.

French bean variety Ooty 3 : A high yielding variety suitable for Temperate zones of Tamil Nadu

Selection for earliness, high yield, quality pods, resistance to pests and diseases are the major aims in the French bean. Selection and identification of French bean variety suitable for cultivation are  needed. Collections were made at the Nilgiris district and based on evaluation, French bean variety Ooty 3 (pole type) was selected as a pure line.  Initially, sixteen different genotypes were collected from different locations and evaluated at Horticultural Research Station, Ooty. A single plant namely PvP5-1 was selected from Nilgiris local based on improvement in pod length, pod number, pod weight, pod circumference and yield per plant. The yield performance of Ooty 3 was superior over check in all the Multi-Location Trials, Adaptive Research Trial and large-scale evaluation trials.  Due to its consistent superior performance, it was released as a French bean variety, Ooty 3 during 2018 duly approved by the Crop Scientist Meet, 2017 held at Tamil Nadu Agricultural University and Tamil Nadu State variety release committee to cater for the needs of Tamil Nadu farmers thereby increasing the yield level.   Keywords: French bean, Ooty 3, high yield, quality, Earliness

Genetic evaluation of the scrotal circumference of beef bulls in the Czech Republic

The objective of the present study was to estimate the genetic parameters for the scrotal circumference of bulls of beef breeds in the Czech Republic. The used database for the years 1996–2020 comprised information on the scrotal circumference measurements from 22 065 bulls of 19 pure breeds and crossbred animals of the Beef Simmental, Charolais, and Hereford breeds. After adjustments, the database contained 16 404 records. To test the influence of systematic fixed effects, the GLM/SAS procedure using the least-squares method was applied. The contemporary group, weight and age of the bulls were included as significant systematic environmental effects (< 0.05). The genetic parameters were determined by a single-trait model using the AIREMLF90 program. The heritability coefficient of the scrotal circumference was 0.27. Environmental correlations of the scrotal circumference with the bull weight were moderate and positive (r = 0.2), but the correlations between the age in days and the scrotal circumference were almost zero (r = 0.03). The results indicate that the scrotal circumference of beef cattle breeds provides sufficiently high genetic variability that can be used to identify individuals with an above-average circumference and, in this way, increase the probability of selection of a young bull with a better reproduction potential.

ATL 1: A high yielding kodo millet variety

A high yielding, input responsive, non lodging varagu culture TNPsc 176 was developed at the Centre of Excellence in Millets, Athiyandal. It is a pure line selection from DPS 63. It is characterized by tufty and medium tall plant stature, strong and sturdy culm with regular, long panicles. It has 10-15 productive tillers/plant and non-shattering grains on the panicle. It matures in 105-110 days and has recorded 2506 and 4394 kg/ha of grain and straw yield, respectively in a total of 223 trials under rainfed conditions during the past eight years of evaluation at national and state levels. The yield was observed to be 12.5 and 13.8 per cent increase in terms of grain and 15.5 and 13.0 per cent increase in terms of straw over the check varieties, CO3 and TNAU 86, respectively.  In view of the superior performance and desirable attributes viz., easy threshability, synchronized maturity, non-lodging growth habit, bold and attractive light brown-coloured grains with good nutritional and cooking qualities, the varagu culture TNPsc 176 was released as ATL 1 during the year 2021, for cultivation in Ariyalur, Cuddalore, Dharmapuri, Madurai, Perambalur, Pudukottai, Salem, Vellore, Villupuram and Virudhunagar districts of Tamil Nadu. Keywords: Kodo, Varagu, yield, non lodging

Dapoli 3: A high yielding variety of finger millet

A high yielding mid-late duration culture DPLN 2 was developed at the Department of Agriculture Botany, College of Agriculture, Dapoli and released as Dapoli 3 during 2020 at the state level and notified by the ministry of Agriculture and farmer welfare, Department of Agriculture and farmer welfare with notification number CG-DL-E-04012022-232406 extraordinary part-II-section 3-subsection (ii) dated 24th Dec. 2021. Dapoli 3 has developed through pure line selection from local germplasm. Out of twenty one culture, the culture DPLN 2 was found promising in respect of yield over check Dapoli 1, Dapoli 2 and PR 202 in station, multilocation and adaptive research trials. It yields an average of 2405 kg/ha of grain under rainfed conditions. Besides high yield culture has semi compact earhead, uniform maturity, non-lodging, continuous spikelets, non-shattering with moderate protein (7.52 %) and calcium (264 ppm) content. The weight of earhead of culture is 8.9 g as compared to 7.2 g of Dapoli 1. The culture recorded a grain yield of 2405 kg/ha which was 26.64 per cent increase over the check Dapoli 1 (1899 kg/ha) in station trails. It recorded a grain yield of 2014  kg/ha which was 13.78 per cent increase over the check Dapoli 1 (1770 kg/ ha) in multilocation trials conducted during Kharif 2016 and 2017 at 13 locations whereas the mean grain yield recorded by culture DPLN 2 (was 1518 kg/ha) which was 12.19 per cent increase over check Dapoli 1(1353 kg/ha) in adaptive research trial conducted in Konkan and Goa region during Kharif 2019. It has given the mean yield of 3228 kg/ha which was 5.76 per cent increase over the national check GPU 45 (3052 kg/ha) and 12.98 per cent increase over the VL 376 (2857 kg/ha) in all India co-ordinated trails tested during kharif, 2019.  Keywords: Finger millet, yield, Semi compact, new variety

Seedling growth promotion and potential biocontrol against phytopathogenic Fusarium by native rhizospheric Pseudomonas spp. strains from Amarillo Zamorano maize landrace

Maize is one of the most important staple crops around the word. In Mexico, Los Altos de Jalisco is an agricultural region with the highest production of maize with rainfed irrigation, an agronomic management based on the use of no longer sustainable agrochemicals, and sowing of coated seeds of different commercial origin. Nowadays, the microbiota associated to the rhizosphere of native landraces is considered a reservoir of microbial resources with the potential to promote plant growth and control diseases. With the aim to find ecofriendly and cost-effective alternatives that can reduce the use of agrochemicals at seed germination and seedling growth of maize crop in Los Altos de Jalisco, this study focused on the search of fluorescent Pseudomonas strains as germination and seedlings growth promoters and biocontrol agents of fusariosis in maize, and highlight the importance of Mexican maize landraces as natural reservoirs of plant growth-promoting microorganisms. Samples of rhizospheric soil and seeds were collected from ten maize landraces and a pure line. Pseudomonas and Fusarium strains were isolated and selected by its antagonistic and pathogenic potential, respectively. Pseudomonas strains were phylogenetically identified by a 16S rRNA gene analysis, and Fusarium strains by the phylogenetic analysis of ITS region. The potential of Pseudomonas strains to promote seed germination and seedling/plant growth was explored through metabolic profiles and bioassays to evaluate bacteria-plant-fungus interactions. A total of 57 Fusarium spp. strains were grouped into four different Fusarium species complexes and 14 fluorescent Pseudomonas strains were classified into four Pseudomonas fluorescens subgroups. Pseudomonas strains displayed plant growth promotion and biocontrol capacity by increasing 38%–66% the dry weight of maize seedlings (p < 0.05), 23%–63% growth-inhibition of different Fusarium strains in dual cultures, and a range of 4.5–20 inhibition score based on a rate scale when inoculated in seeds. Pseudomonas spp. metabolic profiles were diverse, but all the strains proved to be innocuous, and Pseudomonas sp. 4L, 10L and 11L showed desirable enzymatic capacities from an agrobiotechnological approach. Additionally, Pseudomonas sp. 4L increased germination and seedling growth of maize, by increasing 20–51% the number of germinated seeds, 16–38% the length of seedling aerial part, 30–140% seedling length of roots, 15–32% seedling fresh weight, and 21–33% seedling dry weight, and reduced 75–96% the damage generated by Fusarium spp. on naturally infected seeds. This study revealed that Pseudomonas sp. 4L and 11L are regional promising ecofriendly and cost-effective alternatives as adjuvants in the nutritional and phytosanitary management at seed germination and seedling growth of maize crop in Los Altos de Jalisco region, and highlight the importance of the rhizosphere microbiome of Mexican maize landrace as natural reservoir of plant growth-promoting microorganisms.

Fast growing broiler production from genetically different pure lines in Turkey. 1. Parental traits: growth, feed intake, reproduction, and hatching traits.

The aim of the present study was to reveal the trends in age-related growth, feed intake, reproduction, and hatchability traits in 5 pure line (PL) breeders (3 dam [A1: slow-feathering, A2: fast-feathering, A3: slow-feathering] and 2 sire [B1: fast-feathering, B2: fast-feathering]) and their reciprocal two-way cross parent stock (PS) breeders (6 female [A1♂ × A2♀; A1♂ × A3♀; A2♂ × A1♀; A2♂ × A3♀; A3♂ × A1♀; A3♂ × A2♀] and 2 male [B1♂ × B2♀; B2♂ × B1♀]) and to identify heterotic effects in two-way cross PS combinations showing superiority over PL breeders. In the rearing period, 60 females and 15 males in the each PL group, 120 females in each female PS and 120 males in each male PS breeders, and 40 females and 5 males were used in each PL and PS genotype in the laying period. Body weight (BW), average daily feed intake (ADFI), reproductive traits (age at first egg [AFE], age at sexual maturity [ASM], egg number, weekly and total %Lay, egg weight, egg mass), hatching traits (fertility, hatchability of fertile [HOF] and set [HOS] and embryonic mortality), and heterosis (%) values for some traits were assesed. Both males and females of PLs and PSs had different BW at 4 and 8weeks of age (P < 0.01), but had similar BW from 12 to 24weeks of age. The A2, B1, and B2 hens had a higher BW (nearly 4000g) than the others at 31weeks of age (P < 0.01), and B2 hens showed a BW of more than 5000g at 64weeks (P < 0.001). Weekly ADFI per female in rearing, laying, and overall period was not different between groups. The A1 (179days), A3 (183days), two-way cross (from 175.5 to 185.5days) hens started laying at a similar age and earlier than B1 (184days), A2 (192days), and B2 (194days) hens. From AFE to 64weeks, %Lay was the highest in the A1 line (69.7%), lowest in the B1 (45.3%) and B2 (48.8%) line, and between 56.9 and 64.8% in PS breeder hens. The PS eggs tended to have higher fertility, HOF, and HOS, and less embryonic mortality compared to PL eggs. Negative and low heterosis for AFE was observed in PS eggs, while positive heterosis for fertility, HOF, and HOS was generally observed in four-way hybrid eggs. The highest heterosis for the 64-week cumulative egg number was observed in A3 × A2 hens. Our study results show that mating of B1 × B2 males with A3 × A2 females seems more favorable in terms of higher egg or chick production. However, more knowledge is also needed for the overall efficiency of each PS, including the final performance of its hybrids.

Prevalences of Gastrointestinal Parasitic in Dogs and Cats at Kaki 4 and K-5 Clinics Kediri City

Parasitic diseases of the gastrointestinal have a bad impact for dogs and cats. This study was conducted to determine the prevalence, types, and different of maintenance system on dogs and cats in Kaki 4 and K-5 clinics Kediri city. This study used 100 samples of cat and dog feses. The result showed 4% prevalence i.e. 2 samples are positively infected by Ancylostoma sp. (2%), 1 sample is positively infected by Toxocara cati (1%), and 1 sample is positively infected by Ancylostoma sp., Dipylidium caninum, and Toxascaris leonina (1%). Classified by maintenance system, the dogs and cats that maintenance with semi-intensif system prevalence was 2.1% (2/96), while intensif prevalence of 50% (2/4). Based on gender, male prevalence of 7.4% (4/54), while a female was not infected by gastrointestinal parasite. Classified by age, the dogs and cats under age of one year the prevalence of 4.2% (2/47), while those age one year or more prevalence was 3.8% (2/53). Based antiparasitic drugs that given the dogs and cats prevalence was 2.1% (2/96), while not given prevalence of 50% (2/4). Based on breed, the pure breed prevalence of 2.8% (1/36), mix breed prevalence of 12.5% (1/8), while the domestic breed prevalence was 3.6% (2/56).

Latent class analysis of behavior across dog breeds reveal underlying temperament profiles

Latent class analysis (LCA) is a type of modeling analysis approach that has been used to identify unobserved groups or subgroups within multivariate categorical data. LCA has been used for a wide array of psychological evaluations in humans, including the identification of depression subtypes or PTSD comorbidity patterns. However, it has never been used for the assessment of animal behavior. Our objective here is to identify behavioral profile-types of dogs using LCA. The LCA was performed on a C-BARQ behavioral questionnaire dataset from 57,454 participants representing over 350 pure breeds and mixed breed dogs. Two, three, and four class LCA models were developed using C-BARQ trait scores and environmental covariates. In our study, LCA is shown as an effective and flexible tool to classify behavioral assessments. By evaluating the traits that carry the strongest relevance, it was possible to define the basis of these grouping differences. Groupings can be ranked and used as levels for simplified comparisons of complex constructs, such as temperament, that could be further exploited in downstream applications such as genomic association analyses. We propose this approach will facilitate dissection of physiological and environmental factors associated with psychopathology in dogs, humans, and mammals in general.

Coalescing and discriminating offspring from pure line and reciprocal crosses of two African catfishes: Clarias gariepinus and Heterobranchus longifilis

Coalescing and discriminating offspring from pure line and reciprocal crosses of two African catfishes: Clarias gariepinus and Heterobranchus longifilis

Scientific justification of the breeding program of red dairy cattle in the Republic of Belarus

A scientific substantiation of the main directions of the program for creating a domestic breed of red dairy cattle has been developed, which provides for pure breeding and various cross-breeding options to obtain high-producing animals with good reproductive performance and productive longevity.

Analysis of genetic variability and correlation for yield and its attributing traits in F2 population of rice (Oryza sativa L.)

For designing of the breeding programme, analysis of genetic variability and character correlation is crucial in crop improvement. The aim of this experiment was to estimate genetic variability parameters and trait association for 13 quantitative traits which were measured in F2 segregating populations of six crosses containing nine parents. All the F2 populations showed significant GCV and PCV values for productive tillers per plant, grains per panicle, grain yield per plant and straw yield per plant, indicating that these traits may be improved through selection. Plant height, productive tillers per plant, grains per panicle, grain yield per plant and straw yield per plant showed high heritability coupled with high genetic advance, indicating that these traits were controlled by additive gene action and have a good chance of improvement through pure line selection. Grain yield per plant exhibited a strong positive correlation with plant height, panicle length, grains per panicle, straw yield per plant, productive tillers per plant and harvest index in all the six F2 segregating populations. The F2 population of the cross GR 17 × NVSR 2740 demonstrated that more GCV and PCV, high heritability with high genetic advance for the majority of the traits which can be improved by selection. Keywords: Rice, F2 population, Variability, heritability, genetic advance and correlation

Improvement on growth and reduction of kid's mortality through adoption of brooding technique in goats in the mid-hill of Nepal

The mortality of kid's is serious problem in commercial goat farming in Nepal. There are various factors which affect the growth rate and mortality of kids. One of the main factors is rearing management during early age of kids but more research focused on feeding and treatment only. So an experiment was carried out to reveal the effect of brooding management system for growth and mortality of kids in goat at National Goat Research Program, Bandipur, Tanahun of Nepal from October 2020 to February 2021. All together 96 newly born goat's kids were included in this experiment from three pure breeds which were born late October to early November 2020. Among them 32 kids of each breeds of pure Khari, pure Barbari and pure Boer were maintained which were divided in to two equal groups. One group was reared with their mother in normal shed where no any bedding material and extra heating mechanism was provided and another group was reared in well bedded shed and two brooders was provided. Data of birth weight, one month to four months weight of every kids, monthly weight gain and number of death kids were recorded and data were analyzed using IBM SPSS 26. This result showed that breeds, sex and management of rearing system affect significantly (p

Prevalence of Tumours and Tumour-like Lesions in Domestic and Exotic Animals from Lower Silesia and its Surrounds in Poland in 2014-2017.

An analysis of samples originating from domestic and exotic animals from Lower Silesia but also from other parts of Poland was carried out based on research conducted in 2014-2017. The materials used for the study were 11,338 tumour samples taken in vivo during surgery and as biopsies and posthumously during necropsies. They were sent to the Department of Pathology at Wrocław University of Environmental and Life Sciences for histopathological diagnosis. The largest group were canine tumours, of which there were 9,745 (85.95%), followed by feline tumours, totalling 1,397 (12.32%), tumours from exotic animals (186; 1.64%), from horses (7; 0.06%), and from cows (2; 0.02%). A significant number of cases of animals suffering from more than one tumour were also found, which had not been frequently diagnosed previously. The number of neoplasms diagnosed in pets and exotic animals is increasing every year. The average animal age at diagnosis continues to fall. The greatest number of neoplasms were diagnosed in mixed-breed dogs and cats, and the number of tumours in a pure breed strictly correlated with breed's popularity in the research period. Mesenchymal tumours are still the most prevalent type of tumours in dogs, while in cats epithelial tumours predominate. The neoplasm case pattern in animals conforms to that in humans in the same area.

Registration of ‘ARTPEA/BBT/72/B’ and ‘ARTPEA/BBT/22/W’, brown blotch‐tolerant and early‐maturing cowpea cultivars for humid ecologies of Nigeria

AbstractBrown blotch disease, caused by Colletotrichum truncatum (Schew), is one of the most destructive diseases affecting cowpea [Vigna unguiculata (L.) Walp.] in the humid agro‐ecologies of southwestern Nigeria. Development of resistant or tolerant cowpea cultivars was identified as the most economical and effective means of addressing the threat of this disease. Two improved cowpea cultivars, ‘ARTPEA/BBT/72/B’ (Reg. no. CV‐347, PI 700856; also known as Remilekun) and ‘ARTPEA/BBT/22/W’ (Reg. no. CV‐346, PI 700855; also known as Boluyo) (National Code numbers NGVU‐22‐41 and NGVU‐22‐42), were developed through the pedigree breeding method from reciprocal crosses between IT‐95K‐193‐12 and ‘Ife‐Brown’ and released by the Institute of Agricultural Research and Training, Obafemi Awolowo University, Moor Plantation, Ibadan, Nigeria, in 2022. They were bred for early maturity, high yield, and enhanced tolerance to brown blotch disease in the humid agro‐ecologies of southwestern Nigeria. ARTPEA/BBT/72/B and ARTPEA/BBT/22/W along with their parents and other breeding lines were evaluated in 10 locations for 2 yr on 16 farmers’ fields between 2020 and 2021. ARTPEA/BBT/72/B (Remilekun) and ARTPEA/BBT/22/W (Boluyo) are tolerant to brown blotch disease, early maturing (60–75 d), high yielding (1–1.2 t/ha), non‐photoperiod sensitive, and adaptable to Nigeria's humid agro‐ecologies. They can be cultivated twice a year for enhanced cowpea production in Nigeria.

Population Breeding in Pigeonpea: A Review

Issues related to the stagnation of yield in pigeonpea [Cajanus cajan (L). Millsp.] are as old as seven decades or even more. This may be a consequence a number of factors but ineffectiveness of pure line breeding appears on the top of the list as it was the only method used by each and every crop breeder. The natural out-crossing of the crop, always considered a bane, was never used in the pigeonpea breeding until mid-seventies, when a hybrid breeding programme was initiated jointly by ICRISAT and ICAR. Besides this, some population breeding schemes were also suggested and tried on a limited scale in pigeonpea. The authors in this paper have reviewed various aspects of these population breeding methods. It is concluded that the methods such as stratified mass selection and sybrid breeding have good technical base and can be tried for enhancing seed yield in pigeonpea.

Evaluation of Heterosis of Crosses between Clarias gariepinus, Heterobranchus bidorsalis and their Hybrids Collected from Minna Metropolis

Hybridization of Clarias gariepinus (Cl) and Heterobranchus bidorsalis (Ht) and determination of their growth and heterosis parameters were performed. Four crosses (♀ × ♂) were tested: Cl X Cl, Cl X Ht, Ht X Cl, and Ht X Ht. Fifty 14-day-old juveniles from each of the four crosses were stocked separately in tripled plastic bowls. Fifteen fish were randomly selected each week using a fine mesh mosquito net and then weighed on a sensitive scale. The highest percentage of fertilization (58.57%) was recorded in the pure breed (Ht x Ht). The hybrid (Cl x Ht) had the highest hatching rate. Pure breeds recorded the highest condition factor (2.37), and hybrids had the highest feed conversion ratio. The Cl X Cl cross had the highest final mean weight (1980 mg) and the specific growth rate (SGR) of 4.91% / day compared to the other three crosses. Negative heterosis for growth (-14.95%) was observed in hybrids, while hybrid survival showed positive heterosis (26.56%). Poor growth of the hybrids explained the negative heterosis. Therefore, crossbreeds survived better than purebred catfish. There was a significant difference in the specific growth rate between the four genetic groups studied (P&gt; 0.05).