Application of multivariate analysis to identify relationships among useful agronomic characters of cowpea and differentiation of cultivars for vegetable and grain uses

Background. Сowpea (Vigna unguiculata (L.) Walp.) is a thermophilic crop; in most countries it is grown for grain and vegetable uses. Positive results of open-field cowpea production in the southern regions of Russia and the possibility of its cultivation on infertile soils in hot and dry climate imply the need to develop new cultivars suitable for wider introduction into Russian agriculture. It is of paramount importance for cowpea breeders to know the patterns of variability in the relationships among agronomic traits and their characteristics in cultivars grown for different uses (grain and vegetable). Besides, acceleration of the breeding process to a large extent depends on the knowledge of the traits that make it possible to differentiate the source material according to its intended purpose.Materials and methods. For three years, 315 cowpea accessions of various origin from the VIR collection were studied in Astrakhan Province, Russia. Eight useful agronomic characters were examined. The variability and relationships of these characters were assessed in cultivars grown for grain and vegetable purposes using multivariate statistical analyses.Results and discussion. The characters that differentiate grain and vegetable cowpea accessions were identified: the type of seed coat surface, the presence of fiber in ventral and dorsal pod sutures and a sclerenchyma layer in pods valves, and pod length. Discriminant functions were calculated for identification and classification of accessions according to their grain and forage uses. The character (presence of depressions or longitudinal striae on the seed coat surface) diagnosing vegetable cowpea cultivars was pinpointed. Characters associated with high seed yield were identified. For grain cultivars such character is the weight of 1000 seeds, while for vegetable cultivars it is a large-seeded and long-fruit pod.

Studying agronomic characters in new millet accessions from the VIR collection at Yekaterinino Experiment Station of VIR

Background. Adding new plant varieties to the VIR collection is an important effort to preserve the diversity of worldwide bioresources. The millet collection at VIR is formed through the study of acquired accessions, aimed at identification of biological features that have emerged under certain conditions. Such germplasm may be recommended for use in breeding practice. Studying new accessions makes it possible to predict long-term development of the collection.Materials and methods. The study was carried out at Yekaterinino Experiment Station of VIR, Tambov Province, in 2017–2019. New millet accessions added to the VIR collection served as the research material. The study was based on the descriptors and guidelines for Panicum miliaceum L. developed at VIR.Results and conclusions. An assessment was made for such agronomic characters as the growing season, plant height, grain size, grain yield, and resistance to bacteria. The identified accessions exceeded the reference (cv. ‘Gorlinka’) in a number of traits. Earliness was observed in k-10479 (‘Dozh’), k-10481 (‘Zapadnoye’), k-10324, k-10325, k-10478 (‘Nizhnevolzhskoye’), k-10275 (‘Kvartet’), k-10306 (‘Volga 59’), k-10322 (‘Soyuz’), k-10473 (‘Yarkoye 120’), and k-10474 (‘Kavkazskiye zori’). Low plant height was recorded for k-888, k-10324, k-10306, k-10474, k-10479, k-10326, k-10481, and k-10480 (‘Kamyshenskoye’). Large grain size was shown by k-888, k-10325, k-10306, k-10324, k-10479, k-10475 (local), k-10322, k-10473, k-10480, and k-10481. High grain yields under the conditions of the Central Black Earth Region of Russia were demonstrated by the accessions from Belarus (cv. ‘Zapadnoye’, k-10481) and from Chelyabinsk Province (local cultivar, k-888). Medium and strong resistance to bacterial pathogens was observed in k-888, k-10275, k-10473, k-10474, k-10324, and k-10325. The selected accessions can serve as source material for the development of new millet cultivars.

COMMON BEAN (PHASEOLUS VULGARIS L.): ASSESSMENT OF PROTEIN CONTENT IN SEEDS WITH BRIEF DESCRIPTION OF USEFUL AGRONOMIC TRAITS

The catalogue contains the results of protein content assessment in seeds of 216 common bean (Phaseolus vulgaris L.) accessions from the VIR plant genetic resources collection. The data of a long-term study with mean values of characters for each accession are presented. The study of main agronomic characters in the accessions was conducted from 2004 through 2018 in the experimental fields at Astrakhan Experiment Station of VIR. The accessions are described employing eight morphological and agronomic characters important for breeding practice. This catalogue is intended to serve as a tool in source material selection for further breeding process. It may prove helpful for plant breeders and grain legume experts.

Genetic Variability, Heritability, and Genotypic Correlation of Soybean Agronomic Characters

<p>Genetic parameters are important in genetic improvement and variety development. This study aimed to determine the effective characters that can be applied as selection criterion in soybean breeding using genetic parameters. About 100 soybean genotypes were grown in the Muneng Agricultural Technology Research and Assessment Installation from April to July 2020. The trial was conducted using a randomized complete block design. The results showed that high genetic variability was found on days to maturity, number of branches per plant, number of productive nodes per plant, 100-seed weight, and seed yield. The high heritability was shown by days to maturity, plant height, number of branches per plant, and 100-seed weight. All phenotypic correlations were significant, except for the correlation between seed yield and days to maturity, plant height, number of branches, and number of productive nodes. The seed yield had no genotypic correlation with all agronomic characters observed. The genotypic correlation was only significant for plant height and number of productive nodes, number of branches and number of filled pods, as well as number of productive nodes and 100-seed weight. Therefore, the improvement of seed yield can be conducted through direct selection using the seed yield parameter or indirectly using the 100-seed weight.<br /><br /></p>

Correlation, regression and cluster analyses on yield attributes and popping characteristics of popcorn (Zea mays L. everta) in derived savanna and rainforest agro-ecologies of Nigeria

<p class="042abstractstekst"><span lang="EN-US">Information on the genetic and agronomic relationship among the crop characters is important for the breeding programs. This study aimed at determining the relationship among grain yield, popping expansion and other agronomic characters in 19 popcorn lines evaluated in replicated trials at two locations. Correlation analysis was carried out to determine the relationship between agronomic traits while multiple stepwise regression analyses was used to determine the contribution of other agronomic traits to grain yield. Results showed that plant and ear heights as well as cob length exhibited positive and significant association with grain yield. Popping volume showed negative and significant association (-0.45**) with grain yield while 100-grain mass had a negative and significant correlation (-0.37**) with popping volume. Stepwise multiple regression analysis showed that ear height, cob length, plant aspect and 100-grain mass contributed a total of 53.66 % to variation in grain yield, with ear height contributing the highest portion (22.51 %). Cluster analysis grouped popcorn lines into four different clusters, where ‘Small Pearl Shaped’ and ‘Popcorn 33-1-Y’ belonged to cluster II and IV, respectively, showing how divergent they are and possible utilization for hybrid formation. Improvement for popcorn should focus on identifying lines with acceptable level of popping volume and improved on their grain yield and yield attributes.</span></p>

Identification and grouping of pod shattering resistance and agronomic characters performance from several soybean advanced lines

The use of pod-shatter resistant variety is considered effective in reducing yield loss in soybeans. This study aimed to identify and grouping of pod shattering resistance and agronomic characters performance from several advanced soybean lines. The field experiment was conducted in Blitar (Indonesia) from January to April 2021, using 20 soybean advanced lines and two check cultivars. The laboratory study to identify the pod shattering resistance based on the oven-dry method was conducted in the Breeding Laboratory of ILETRI, Malang. The pod shattering resistance of 20 advanced lines was classified into five very resistant genotypes, three resistant genotypes, two moderate genotypes, nine susceptible genotypes, and a very susceptible genotype. The pod shattering resistance has a significant negative correlation with the pod width (r = -0.472*). A wider pod resulted in a low percentage of shattering. The agronomic performance varied among all genotypes. Selection for pod shattering resistance and agronomic performance obtained two lines (G511H/Anjas//Anjas///Anjas-3-1 and Dega/Degra-2-105) as high yielding and very resistant to pod shattering. Those lines were suggested to be tested across diverse environments to determine their yield potential and stability.

Identification of Pod Shattering Resistance and Associations between Agronomic Characters in Soybean using Genotype by Trait Biplot

Background: Pod shattering has become the major problem in soybean production. The research aims to identify the pod shattering resistance and to assess the agronomic performances of 50 soybean genotypes and the association among agronomic characters. Methods: The research materials were 50 soybean genotypes which consisted of 47 lines derived from routine crossing programs and three check cultivars. The field experiment was arranged in a randomized block design with two replications. The data were observed for yield and its component traits. The oven-dry method was performed in the laboratory to assess the pod shattering resistance. Result: Variation among genotypes was found in the pod shattering resistance and agronomic characters. The genotype by trait biplot graph showed that pod shattering was negatively correlated with the days to maturity and plant height, but positively correlated with the seed size. Soybean genotypes of Grob/G100H-1-588 and G100H/Mhmr-4-993 were resistant to pod shattering and have a high seed weight per plant. These genotypes were potential for further varietal development or could be used as gene sources in the soybean improvement program for pod shattering resistance.

Evalu ation of potato hybrids according to tuber flesh darkening and other useful agronomic characters under the conditions of Kirov Province

Background. Resistance of raw and boiled tuber flesh to darkening when potato is processed into potato-based products or consumed directly is an important requirement for new potato cultivars. Identification of hybrids resistant to tuber flesh darkening would contribute immensely to future breeding work.Materials and methods. Parent forms and hybrid progeny of potato were tested for five years (2016–2020) in Kirov Province using the methods and technologies approved for potato breeding process. The progeny of 10 cultivars used as pollinators was analyzed.Results and conclusions. Cultivars with high levels of resistance to the darkening of raw tuber flesh were selected in the collection nursery. A total of 62 accessions (or 24%) out of 256 were identified for the absence of darkening or only small traces thereof (8 points) in raw tubers. Medium and strong darkening of the flesh (4–5 points) was recorded for 45 accessions. Analyzing the progeny of pollinator cultivars showed an increased occurrence of hybrids resistant to tuber flesh darkening in the progeny of cv. ‘Manifest’: 71% of the studied hybrids had non-darkening flesh (9 points). Manifestation of tuber flesh darkening was found to depend on weather conditions during the growing season: the higher was the air temperature, the weaker was the darkening of raw tuber flesh, but when the soil moisture during tuberization was high, tuber flesh became more darkened. A statistically significant relationship was observed between the darkening of boiled tubers and the content of crude protein (r = 0.74) and vitamin C (r = 0.79). Hybrid 179-10 was identified for high productivity (32.5 t/ha) and crude protein content (1.54%), while the highest resistance to the darkening of raw and boiled potato tubers was registered in hybrid 72-13.

Enhancement of agronomic traits and yield of rice var. ADT 43 grown in typic ustifluvent soil through silicon fertilization

Rice is a rich accumulator of silicon and its supply is essential for the growth and economic yield of rice. Hence, a field experiment was conducted in sandy clay loam soil belonging to Padugai series (Typic ustifluvent) at farmers holding in Kuttalam block, Mayiladuthurai district, Tamil Nadu to assess the role of silicon in improving agronomic characters and yield of rice ADT 43, Oryza sativa. The treatments included T1 - Recommended dose of fertilizer (RDF), T2 - RDF + Potassium silicate (FS) - 0.25%, T3- RDF + FS - 0.50%, T4 - RDF +FS - 1.00%, T5­ -RDF + FS - 0.25%, T6 - RDF + FS - 0.50%, T7­ - RDF + FS - 1.00%, T8 - RDF + SA - 50 kg ha-1, T9 - RDF + SA - 100 kg ha-1 and T10 - RDF + SA- 150 kg ha-1. From T2 to T4, the foliar spray was done at tillering stage and from T5 to T7, the foliar spray was done at tillering and panicle initiation stage. The silicon was applied through FS with the rice crop. The soil application of silicon relatively recorded higher growth and yield compared to foliar application. Besides improving different agronomic characters of the rice, the soil application of 50 kg Si ha-1 registered the highest grain yield (6183.3 kg ha-1) and straw yield (6740 kg ha-1) and was comparable with a single foliar spray of 1% Si. Growth and rice yield increased with Si concentration of 0.25% to 1%. Thus, the soil application of silicon @50 kg ha-1 through potassium silicate is advocated to realize maximum rice yield.