One of approaches to maintain the yield stability of the lowland tropical wheat is the use of secondary traits in the selection process. The identification of these characters requires a statistical approach in the form of genetic parameter analysis and multivariate analysis. The objective of this study was to determine the secondary traits of adaptive wheat mutants in the lowlands through the use of genetic parameters and multivariate analysis on the parameters. The study consisted of three field trials conducted in three different regencies, namely Jeneponto (135 m above sea level (asl)), Maros (100 m asl) and Bantaeng (125 m asl). The study used a nested design, where replications were nested in the environments. The genotype factors consisted of 20 genotypes repeated three times. 11 characters were observed including vegetative and reproductive characters. The analysis used consisted of repeatability, correlation, cluster analysis, principal component analysis, factor analysis, and cross print analysis. The overall results of the analysis indicate that the number of productive tillers is the main secondary trait for the selection of adaptive wheat in the lowlands. The character can be recommended for selection criteria in testing wheat lines in the lowlands to make an effective selection.

Genetic Parameters and Multivariate Analysis to Determine Secondary Traits in Selecting Wheat Mutant Adaptive on Tropical Lowlands

Comparison of drought tolerance of crop plants is important for planning efficient cropping strategies and increasing yield production. The objective was to investigate the effects of drought stress including control (S1), 80 (moderate, S2) and 60% (severe, S3) of crop essential irrigation (determined by evaporation from the Class A evaporation pan) on grain yield and nutritional quality of different corn (Zea mays L.) (Maxima (sensitive) and 704 (tolerant)) and sorghum (Sorghum bicolor (L.) Moench) (Kimia (sensitive) and Payam (tolerant)) genotypes. The experiment, conducted in 2019, was a split plot based on randomized complete block design with three replicates. Plants yields and nutritional quality including relative water content (RW), fiber, protein, starch, tannin, and chlorophyll were measured. Although water stress did not significantly affect RW in corn, it significantly affected RW in sorghum. Fiber concentration was the highest at the severe stress in both corn genotypes (9.36% in 704 and 10.35% in Maxima), and sorghum Payam genotype (14.54%). The lowest (13.29%) and the highest (14.35%) corn protein content were obtained for Maxima in the medium and control level of stress, and for 704 genotype it ranged from 13.51 to 13.77%. Sorghum protein was the highest in the sensitive and tolerant genotypes in control and severe stress, respectively. Treatments S3 and S2 resulted in the highest (14.58%) and the lowest (12.47%) protein content for sorghum Kimia genotype. Although sorghum plants were tolerant in stress conditions, corn plants could also tolerate the stress up to some level by adjusting their physiological characteristics. 

Corn (Zea mays L.) and sorghum (Sorghum bicolor (L.) Moench) yield and nutritional quality affected by drought stress


 The development of tolerant rice varieties using doubled-haploid technology is necessary to speed up the release of a variety tolerant to salinity stress. However, this requires a reliable screening method and selection index model for enhancing selection effectiveness. One approach is through the development of a selection index based on factor analysis under soil salinity screening in the greenhouse. The objective of this study was to develop a selection index model based on factor analysis and select tolerant doubled-haploid lines under high salinity conditions. The experimental design used was a split-plot design with salinity stress treatments as the main plot, i.e., normal (0 mM NaCl) and saline (25 mM NaCl ~ 5.6–5.8 dS/m) and 42 genotypes as the subplot. The genotypes consisted of 36 doubled-haploid lines, four commercial varieties, and two check varieties. The results indicated that a salinity selection index model involving yield and productive tiller traits could be used for selecting rice genotypes tolerant to salinity stress in soil artificial screening. This index which was developed through a combination of factor analysis, stress tolerance index (STI), and path analyses have identified 15 doubled haploid rice lines which were considered as good tolerant lines under salinity stress in soil artificial screening.


Salinity tolerance selection of doubled-haploid rice lines based on selection index and factor analysis

Cluster heatmap for screening the drought tolerant rice through hydroponic culture

The search for productive germplasm adapted to adverse conditions is an important action to mitigate the harmful effects of climate change. The aim was to identify the yield potential of 50 popcorn inbred lines grown in field conditions, in two crop seasons (CS), and under contrasting water conditions (WC). Morphoagronomic, physiological, and root system traits were evaluated. Joint and individual analyses of variance were performed, in addition to the multivariate GT bip-lot analysis. Expressive reductions between WC were observed in 100-grain weight (100 GW), popping expansion (PE), grain yield (GY), expanded popcorn volume per ha (EPV), row number per ear (RNE), plant height (PH), relative chlorophyll content (SPAD), and nitrogen balance index (NBI). It was found that the SPAD, 100 GW, GY, PE, and grain number per ear (GNE) traits had the most significant impact on the selection of genotypes. Regardless of WC and CS, the ideal lines were L294 and L688 for PE; L691 and L480 for GY; and L291 and L292 for both traits. SPAD, 100 GW, and GNE can contribute to the indirect selection. Our work contributes to understanding the damage caused by drought and the integration of traits for the indirect selection of drought-tolerant popcorn genotypes.

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All Are in a Drought, but Some Stand Out: Multivariate Analysis in the Selection of Agronomic Efficient Popcorn Genotypes

. Fadhli N, Farid M, Rafiuddin, Efendi R, Azrai M, Anshori MF. 2020. Multivariate analysis to determine secondary characters in selecting adaptive hybrid corn lines under drought stress. Biodiversitas 21: 3617-3624. The development of adaptive hybrid corn varieties under drought stress needs an effective selection. Multivariate analysis has been reported can increase the effectiveness of selection in plants by attaching the secondary characters in the selection. Therefore, this concept also can be applied to develop adaptive corn varieties under drought stress. The objectives of this study are to determine the main secondary characters and select the best hybrid lines adaptive to drought stress. The experiment was arranged by a nested design, where replications nested under two environmental conditions, namely normal and drought stress. The main factor was genotypes consisted of 30 genotypes and was repeated three times. Moreover, the observations of this research consisted of 20 variables. The result of this research showed that the weight of harvested cob was an effective secondary character as a selection criterion along with productivity in selecting adaptive maize genotypes under drought stress. The number of green leaves was the character outside of the yield component could be as an alternative secondary character besides the weight of harvested cob. The selection results based on the weight of the harvested cob and productivity resulted in 12 hybrid corn lines considered adaptive to drought stress.

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Nur Fadhli

Papers

Multivariate analysis to determine secondary characters in selecting adaptive hybrid corn lines under drought stress