Evaluation of Potato Genotypes for Plant and YieldCharactersin Field at Dailekh

A field experiment was conducted at Horticulture Research Station (HRS), Dailekh, in Mid-Western hills of Nepal during 2019 and 2020, to evaluate the performance of ten potato genotypes for plant, and tuber yield characters. The potato genotypes were evaluated during spring season in a randomized complete block design with three replications. The genotypes showed highly significant difference for all the traits except tuber emergence. The mean squares for the year were also significant for all the traits except tuber emergence, stem numberplant -1 and total tuber yield. The interaction between genotypes and years did not show significant differences in all the traits except stem numberplant -1. Genotype CIP392797.22 produced more marketable yield (27.5 tha -1) and total tuber yield (30.2tha -1) than all other genotypes. The genotype CIP392797.22 is characterized as medium maturing, oval-shaped and dark red-skinned one with shallow eye depth in the tuber, and it imparted 13.2% higher marketable yield than Kufri Jyoti (24.3 tha -1). Thus, the genotype CIP392797.22 is recommended to evaluate on-farm for the verification and up-scaling among farmers at Mid-Western Nepal.

Genomic regions of Solanum tuberosum L. associated with the tuber eye depth

Potato (Solanum tuberosum L.) is one of the most important food crops in the world. The genome of this potato species is autotetraploid and has a high level of heterozygosity, also this potato species is a cross-pollinated plant. These characteristics complicate the genetic analysis and breeding process. The tuber’s eye depth is an important trait that affects the suitability of potato varieties for processing. Potato breeding for this trait is based on phenotypic assessment. Identification of the loci that control tuber eye depth would allow diagnostic markers for the marker-assisted selection to be created. The aim of this study is to search for loci associated with the eye depth by analyzing Solanum tuberosum varieties from the GenAgro collection of the Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences, genotyped using the Illumina 22K SNP potato array DNA chip. The 24 significant markers associated with the “eye depth” trait were identified using 15,214 SNP markers genotyped with the Illumina 22K SNP potato array chip and the general linear model (GLM) taking into account the population structure. Data obtained showed the presence of SNPs in four genomic regions: on chromosome 4 (1 marker in the 3.92 Mb area), 5 (1 marker in the 4.67 Mb area) and 10 (1 marker in the 4.87 Mb area and 21 markers in the region between 48.1–48.9 Mb). The results of localization in the region 48.1–48.9 Mb of chromosome 10 correspond to previously published studies, the remaining three regions were detected for the first time. DNA sections containing SNPs linked to the tuber’s eye depth were studied in the SolTub_3.0 potato genome assembly (https:// plants.ensembl.org/). KASP markers were developed based on the data obtained. It will be possible to screen the breeding material and to breed the varieties more effectively using current markers associated with a shallow tuber’s eye depth.

Combining ability analysis of tuber yield and related traits in potatoes

In potatoes (Solanum tuberosum L. 2n=4x=48) both the general combining ability (GCA) effects of parents and specific combining ability (SCA) of crosses are important in conditioning traits of economic importance. The objective of this study was to determine the combining abilities for tuber yield and its components on seven high-yielding commercial cultivars of potato and advanced potato clones. Significant differences were found between the parents in the all of traits that are associated with high genetic diversity between parents. GCA for tuber form, length of stolon and number of tuber per plant were high and for stem height, tuber skin appearance and eye dept were low. Heritability estimated from 49 percent in the number of stem to 84 percent in tuber skin appearance. Both heritability and genetic advance as percent of mean estimates were high for tuber yield, tuber form, length of stolon, tuber size, and number of tuber per plant and tuber size uniformity. AS10, AS12, AS14 and UT43 clones was best general combiner for the tuber yield, tuber size uniformity, eye depth, tuber dry matter and length of stolon. The SCA effects were the highest in the cross Savalan?UT43, Luca?AS20, Stbr2?Savalan and Picasso?HS in the traits were considered. Savalan and UT43 parents used in the crosses also have high GCA in studied traits. Finally results showed that Savalan, UT43, AS10, AS12 and AS14 in the studied traits was the high GCA and better than other parents.

Early Generation Selection within a Diploid Hybrid Solanum tuberosum Groups Phureja and Stenotomum Population for the Intense Yellow-flesh Creamer Potato Market

Consumer demand for specialty market potatoes has been growing. Cultivated South American diploid potatoes possess great variation for skin and flesh colors, shape, and taste. A long-day adapted population of Solanum tuberosum groups Phureja and Stenotomum (phu-stn) was evaluated for characteristics associated with the type known as papa criolla or papa amarilla in South America. Tubers have intense yellow flesh and may be fried or roasted and eaten whole. A U.S. northern location (Maine), representative of a seed growing region, and two southern locations (Florida and New Mexico), representative of potato growing regions near large Hispanic populations, evaluated yellow-fleshed clones selected within a phu-stn population. Agreement between selectors at two locations was greater than 50%. Tuber skin color and shape were highly correlated between locations; flesh color and tuber dormancy moderately so; eye depth had low correlation between locations; and appearance and skin texture had low or no correlation between locations. Tuber dormancy was generally short, but a few longer dormant clones were identified. There were significant differences among clones for yields, with the highest yields occurring in Maine. More intense evaluations are planned for a subset of these clones before possible release as new varieties. Future breeding efforts will be undertaken to lengthen tuber dormancy in this population.

Effect of ractopamine on digestible-lysine requirement for finishing barrows under thermoneutral conditions

The purpose of the present study was to determine the digestible-lysine (Lys) requirement in diets supplemented or not with ractopamine (RAC), so as to maximise performance and carcass characteristics for finishing barrows reared at thermoneutral conditions. In total, 128 high-lean commercial hybrid barrows with an initial bodyweight of 78.2 ± 4.3 kg were distributed in a completely randomised block design, in a 4 × 2 factorial arrangement (four Lys concentrations: 0.730%, 0.830%, 0.930% and 1.030% and two RAC inclusions: 0 and 10 mg/kg), with two animals per pen and eight pens per treatment. Lys concentrations tested significantly (P < 0.05) affected digestible-lysine intake, and the absolute (g) and relative (%) lean meat content, regardless of RAC inclusion. When diets were RAC-supplemented, feed conversion rate of animals was improved and, in addition, final bodyweight, daily bodyweight gain, loin eye area, loin eye depth, and absolute (g) and relative (%) carcass lean meat content increased (P < 0.05). RAC inclusion also decreased (P < 0.05) backfat thickness and the colour values a* and b* of finishing pigs. Therefore, on the basis of our results, it can be inferred that the best performance and carcass characteristics for finishing barrows reared at thermoneutral conditions were obtained at 1.030% and 0.730% Lys respectively, corresponding to an estimated daily Lys intake of 34.3 g and 24.2 g, independently of the diet RAC concentration.

Biometric sexual and ontogenetic dimorphism on the marine catfish Genidens genidens (Siluriformes, Ariidae) in a tropical estuary

This paper aims to study the ontogenetic sexual dimorphism of Genidens genidens in Guanabara Bay, southeastern coast of Brazil. Altogether 378 specimens were anayzed (233 females and 145 males) with total length ranging from 13.3 to 43.5 cm. Specimens were measured for 12 body measurements, sex was identified and maturity stages were recorded and classified. Pearson’s linear correlation reveled a significant positive correlation between total length and all other body measures, except for base adipose fin, mouth depth and eye depth for immature females. Analyses nested PERMANOVA desing showed significant differences between maturity stages for each sex, between sexes considering or not maturity stages, indicating a variation in morphometric characteristics driven by sexual dimorphism. Differences among all maturity stages were also found, indicating an ontogenetic morphological difference. But immature individuals didn’t differ between sexes indicating that differentiation patterns starts with sexual development. The most important measures differing males and females were related to head characteristics, which appears to be key parameters to evaluate sexual differences. Due to male incubation of fertilized eggs and juvenile individuals <59 mm in their oral cavity, head measures are proposed to be sex dimorphism not related to reproduction, but with post reproductive fase due to ecological and biological needs. [L1]Modificated as suggested by Reviewer E.

Expected response to early-generation selection for yield and tuber appearance traits in potatoes

The aim of this study was to evaluate the performance of potato clonal families, and to estimate genetic variance, heritability and the expected response to selection of tuber yield and appearance traits in early generations. Twelve potato families were obtained from crosses between two groups of randomly-selected genotypes, including Eliza, C1730-7-94, and C-1742-8-95 in group 1; and Shepody, Asterix, Caesar, and White Lady in group 2. The crosses were made in factorial design (3 genotypes x4 genotypes), and each family consisted of 75 genotypes. Experiments were conducted in the fall of 2010, with a seedling generation under greenhouse conditions, and in the fall of 2011, with a clonal generation under field condition. High heritability estimates suggest that mild to moderate selection can be applied in the seedling generation to eye depth, eyebrow prominence, tuber curvature, flattening and shape uniformity. The C1742-8-95/White Lady stood out as a superior cross, as did all other crosses with White Lady, regarding tuber appearance and yield traits.