This study was conducted to assess the genetic variability and correlation of phenotypic characteristics in 12 tomato (Solanum lycopersicum L.) genotypes including 11 WorldVeg and one commercial variety (Pusa Ruby) in Terai (plain) region of Nepal in 2021–2022. This experiment was laid out in a randomized complete block design with three replications. The phenotypic traits, including days to 50% flowering, plant vigor and height, fruit number/plant, fruit yield, fruit weight and diameter, fruit firmness and fruit pericarp thickness, and total soluble solids (TSS) content of the fruits, were studied. Analysis of variance revealed significant differences among the genotypes for all the traits except for plant vigor. The genotype of AVTO1705 resulted the highest fruit yield (2.9 kg/plant) than Pusa Ruby, a commercial check (0.5 kg/plant). The phenotypic coefficient of variation (PCV) was higher than the genotypic coefficient of variation (GCV) for all the traits and PCV values were maximum for the number of fruits, fruit yield, and fruit weight. High PCV, GCV, and genetic advance (GA) were observed for yield, fruit weight, and plant height, respectively, indicating the additive gene effect. High heritability for fruit yield/plant and plant height inferred the phenotypic selection for their genetic improvement. Fruit yield was significantly (P<0.05) positively correlated with the fruit number and fruit weight, and direct selection of these traits are reliable for yield improvement in tomato.

The invasive red swamp crayfish, Procambarus clarkii, is native to southcentral United States and northeastern Mexico. Recently, it has been being spreading in the wild in South Korea. However, its primary sources, introduction routes, establishment, and expansion in South Korea remain unclear. Here, we analyzed genetic diversity and population genetic structures of its domestic natural populations during early invasion, commercial stock from local aquaria (a suspected introduction source), and original United States population using mitochondrial COI gene sequences for 267 individuals and eight microsatellite markers for 158 individuals. Natural and commercial populations of P. clarkii showed reduced genetic diversity (e.g., haplotype diversity and allelic richness). The highest genetic diversity was observed in one original source population based on both genetic markers. Despite a large number of individuals in commercial aquaria, we detected remarkably low genetic diversity and only three haplotypes among 226 individuals, suggesting an inbred population likely originating from a small founder group. Additionally, the low genetic diversity in the natural population indicates a small effective population size during early establishment of P. clarkii in South Korea. Interestingly, genetic differentiation between natural populations and the United States population was lower than that between natural populations and aquarium populations. This suggests that various genetic types from the United States likely have entered different domestic aquariums, leading to distinct natural populations through separate pathways. Results of our study will provide an insight on the level of genetic divergence and population differentiation during the initial stage of invasion of non-indigenous species into new environments.

Ionizing radiations have been effective mutagen to overcome the limitation of the useful genetic resources in natural environment. This study was conducted to investigate an effect of proton beam on germination, growth patterns in the irradiated dandelion (Taraxacum officinale), and genetic variation in 12 morphological mutants induced in proton-beam irradiated dandelion. Percentage germination rate was drastically decreased over 250Gy. The lethal dose 50 (LD50) of germination was estimated between 250 Gy to 500 Gy. Significant decreases in growth patterns (plant height, number of leaf and fresh weight) were observed by increase of dose (Gy) of proton beam irradiation. According to the correlation analysis between dosage and growth factors, the orders of compactness of correlation were germination, plant height, fresh weight and number of leaf, respectively. Twelve morphological variants such as, dwarf, color, plastid, growth and leaf shape were screened at 50 to 250 Gy of the beam irradiation. As a result of ISSR analysis of the 12 variants, out of 33 bands detected overall, 8 bands were identified to be polymorphic with a rate of 24.2% at the control group. While 33 bands detected overall, 21 bands were identified to be polymorphic with a rate of 63.6% at the proton beam irradiation. The result indicates that the dandelion with proton beam treatment might be promoted variation at DNA level

Breeding the whole crop siliage rice cultivar basically requires priority in high biomass and grain yield and tolerance biotic and abiotic stresses. In this context, AA genome wild rices are potential resources to broaden genetic variability for whole crop silage cultivar. We have developed several introgression populations from crosses with three AA genome wild rices, O.glaberrima, O.rufipogon, and O.longistamina. Among these populations, the three BC4F8 near isogenic lines (NILs) derived from a cross of Milyang 23 and O.glaberrima(acc. 101154) could produce the high-yielding lines surpassing Milyang 23 by 20% in grain yield. Introgression lines from crosses with 4 accessions of O.rufipogon with japonica rices, Hwaseongbyeo and Ilpumbyeo had huge agronomic variability and very tall and vigorous lines possessing culm length of 125 ∼ 187cm were selected as promising potential parents to improve biomass of existing cultivars. These selections with high yield potential and biomass will be crossed to create another gene pool to combine high yield and biomass and anther culture breeding could be useful to develop genetically fixed F2 lines with both traits.

Twenty-five promising lowland rice genotypes of eastern India were studied for genetic variability in twelve quality characters and grain yield. Analysis of variance for all the characters indicated significant differences among genotypes for all the phys

A study on genetic variability and association of yield attributing characters with grain yield was carried out using 35 deepwater rice genotypes. High genotypic co-efficient of variation (GCV) was observed for plot yield, EBT/m2 , plant height and days to 50~% flowering (DFF). For all the traits, estimates of the phenotypic co-efficient of variation (PCV) were higher than GCV, indicating presence of environmental influence. High heritability and genetic advance was observed for plot yield, EBT/m2 and plant height. Plot yield had significant positive association with test weight, EBT/m2 and DFF. However, test weight had the maximum direct effect on grain yield

This study was conducted to investigate morphological characteristics of Korean local garlic varieties and to define the genetic variability and the correlations amongthe characters associated with yield. The plant height, the leaf sheath diameter, the nubmer of leaves, and bulb weight were significantly increased in the garlic plants from heavier seed bulbs. The proportation of six clove bulbs was more than 60% in Seosan variety and this was not realted with the number of cloves in seed bulb. While more than 70% bulbs in Jeoksung and Danyang varieties cultivated in paddy field were composed of 6 or 7 cloves, majority of the bulbs of Euisung and Danyang varieties cultivated in upland were composed of bulbs with 7 cloves or more. The highest genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) were observed in bulb weight. GCV and PCV also showed high value in leaf sheath diameter. Thus, there is a greater scope for selection of these characters. The small difference between PCV and GCV values in plant height indicates that the environmental influence would be limited in this character. High heritability was observed of plant height (56.76%) and bulb weight (45.95%). And the weight per bulb (34.24%) exhibited highest genitic advance followed by leaf sheath diameter (18.8%) and plant height (9.61%), and those would be the ideal characters for selelction.

본 실험은 대두육종을 위한 유전자원으로서 우리나라 재래종 825계통을 대상으로 2년간 재배하면서 그 집단내의 유전적 변이성과 특성을 구명하고 이들을 이용한 다수확 품종의 육성에 필요한 정보를 획득하는데 목적이 있으며 그 결과는 다음과 같다. 1. 단위면적당 평균 수량은 1,004.1kg/ha이고 대부분의 계통이 795kg에서 1,245kg의 수량성을 보였으며 백립중은 8.6gr∼44.4gr의 범위에서 평균 23.0gr이였다. 성숙기는 평균 144.7일로써 대부분의 계통이 만숙성이였고 초장 및 주당협수의 변이폭은 비교적 컸다. 2. 단백질함량은 평균 42.83%이고 40.7%∼44.2%, 지방함량은 평균 17.46%로서 전체계통의 70%가 16.5%∼19.0% 범위에 속해 있어 저지방성임을 나타내었다. 3. 유전분산은 수량과 초장 및 주당협수가 컸고 백립중 및 성숙기도 비교적 컸으나 단백질과 지방함량은 적은 유전분산을 보였다. 4. 백립중, 초장 및 주당협수의 유전력과 선발에 대한 기대치는 비교적 높았으며 성숙기의 유전력은 높았으나 선발효율은 낮았는데 그 원인은 재래종 집단의 표현형분산이 적은데 있다고 할 수 있다.