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Maize productivity, reliant on nitrogen availability, is crucial for the Indonesian economy. Previous research found organic fertilizers had minimal effects on the Local variety ‘Tambin’, widely used by smallscale farmers. This study explored varietal responses to nitrogen fertilization using a split-plot randomized complete design with four nitrogen rates (0, 46, 138, and 184 kg N ha−1) as main plots, and maize varieties (Hybrid ‘BISI-18’, Composite ‘Sukumaraga’, and Local ‘Tambin’) as sub-plots. Results showed significant effects of nitrogen rates and maize varieties on growth variables (plant height, stem diameter, and number of leaves). The ‘Tambin’ variety performed best at 138 kg N ha−1, with higher plant heights, while Hybrid ‘BISI-18’ and Composite ‘Sukumaraga’ showed the greatest increases in height and stem diameter at 46 kg N ha−1.

The genotype evaluation process requires analysis of GxE interactions to ascertain the responsiveness of a genotype to various environments, including the development of early maturing rice. However, the concept of interaction is relatively specific to grain yield. In contrast, grain yield is highly polygenic, so assessment should be carried out with multivariate approaches. Therefore, multivariate assessment in evaluating GxE interactions should be developed, especially for early maturing rice genotypes. The study aimed to develop a comprehensive multivariate approach to improve the comprehensiveness and responsiveness of GxE interaction analysis. The study was conducted in Bone and Soppeng districts, South Sulawesi, Indonesia, in two seasons. The study used a randomized complete block design, where replications were nested across two seasons and locations. Two check varieties and five early maturing varieties were replicated three times in each environment. Based on this study, a new approach to GxE interaction analysis based on multiple regression index analysis, BLUP analysis, factor analysis, and path analysis was considered adequate, especially for evaluating early maturing rice. This approach combined days to harvest, biological yield, and grain yield in multiple linear regression with weighting based on the combination of all analyses. The effectiveness of the GxE interaction assessment was reflected by high coefficient of determination (R2) and gradient (b) values above 0.8 and 0.9, respectively. Inpari 13 (R2 = 0.9; b=1.05), Cakrabuana (R2 = 0.98; b=0.99), and Padjajaran (R2 = 0.95; b=1.07) also have good grain yield with days to harvesting consideration, namely 7.83 ton ha-1, 98.12 days; 7.37 ton ha-1, 95.52 days; and 7.29 ton ha-1, 97.23 days, respectively. Therefore, this index approach can be recommended in GxE interaction analysis to evaluate early maturing rice genotypes. Furthermore, Inpari 13, Cakrabuana, and Padjajaran are recommended as adaptive early maturing varieties. [ABSTRACT FROM AUTHOR]

Foxtail millet hybrid development encounters challenges due to its self-pollinating nature, small florets, and tool availability for confirming true hybrid. Our research aimed to assess flowering phenology and explore artificial hybridization employing SiDREB2 based-SNAP marker. The research consisted of three experiments. The first experiment focused on the panicle phenology of foxtail millet, while the second experiment focused on floret phenology and reproductive organs. The artificial hybridization successfulness was validated with SNAP markers based on the SiDREB2 gene in the third experiment. Observations on two genotypes (ICERI-5 and ICERI-6) revealed panicle initiation at 49-69 days after planting (DAP), with anthesis occurring 6 days after panicle emergence (DAPE). Florets exhibited the formation of reproductive organs at 3 DAPE, delineating distinct stages of pollen development leading up to anthesis. Our findings emphasized the significance of implementing male-sterile induction treatment at 4 DAPE to regulate pollen development for successful hybridization by 6 DAPE. The hybrid evaluation revealed varied germination rates and confirmed hybrid percentages across different crossing series, validated by SiDREB2-based SNAP marker. ICERI-5xBotok-4 exhibited high germination but a low confirmed hybrid percentage, while Botok-4xICERI-5 and Botok-10xICERI-6 showed the opposite trend. Reciprocal crossings showed unilateral incompatibility in confirmed hybrid percentage. [ABSTRACT FROM AUTHOR]

Introduction: Breeding for oil palm resistance against basal stem rot caused by Ganoderma boninense is challenging and time-consuming. Advanced oil palm gene pools are very limited, hence it is assumed that parental palms have experienced genetic drift and lost their resistance genes against Ganoderma. High-throughput selection criteria should be developed. Metabolomic analysis using 1H nuclear magnetic resonance (NMR) spectroscopy is easy, and the resulting metabolite can be used as a diagnostic tool for detecting disease in various host-pathogen combinations. Objectives: The objective of this study was to identify metabolite variations in Dura (D) and Pisifera (P) parental palms with different resistance levels against Ganoderma and moderately resistant DxP using 1H NMR analysis. Methods: Leaf tissues of seven different oil palm categories consisting of: resistant, moderate, and susceptible Dura (D); moderate and susceptible Pisifera (P); resistant Tenera/Pisifera (T/P) parental palms; and moderately resistant DxP variety progenies, were sampled and their metabolites were determined using NMR spectroscopy. Results: Twenty-nine types of metabolites were identified, and most of the metabolites fall in the monosaccharides, amino acids, and fatty acids compound classes. The PCA, PLS-DA, and heatmap multivariate analysis indicated two identified groups of resistance based on their metabolites. The first group consisted of resistant T/P, moderate P, resistant D, and moderately resistant DxP. In contrast, the second group consisted of susceptible P, moderate D, and susceptible D. Glycerol and ascorbic acid were detected as biomarker candidates by OPLS-DA to differentiate moderately resistant DxP from susceptible D and P. The pathway analysis suggested that glycine, serine, and threonine metabolism and taurine and hypotaurine metabolism were involved in the oil palm defense mechanism against Ganoderma. Conclusion: A metabolomic study with 1H NMR was able to describe the metabolite composition that could differentiate the characteristics of oil palm resistance against basal stem rot (BSR) caused by G. boninense. These metabolites revealed in this study have enormous potential to become support tools for breeding new oil palm varieties with higher resistance against BSR. [ABSTRACT FROM AUTHOR]

One strategy currently being developed to increase rice (Oryza sativa L.) productivity is using a multi-canopy cropping system in rice cultivation. This method involves planting tall and short rice genotypes in the same hill. The objective of this experiment was to estimate the genetic parameters and response to selection in multi-canopy rice. Each experiment was arranged in an augmented randomized complete block design with five replications for the checks. In the first planting season, 200 F3 families from IPB196 and IPB197 populations were planted in monoculture and multi-canopy as the short genotypes. IPB187-F-40-1-1 was used in multi-canopy as the tall genotype. Selection of 25% based on grain weight per hill of short genotype in multi-canopy was performed, and 50 families were selected and their F4 seeds were planted in the second season along with the same tall genotype. The results indicated the genotype × cropping system was significant for grain weight per hill in the F3 and F4 generations. Grain weight per hill has a similar realized h² ns in the multi-canopy (0.58) with monoculture (0.54). Meanwhile, the response to selection in multi-canopy (3.60) was higher compared to monoculture (2.09), and therefore the selection of rice lines for a multi-canopy system should be conducted in the multicanopy environment. A selection percentage of 5% resulted in a higher response to selection. These findings may provide insight into the acceleration of breeding rice varieties for the multi-canopy system. [ABSTRACT FROM AUTHOR]

Setaria italica L. or foxtail millet is known for its nutritious grains and adaptability to unfavorable environmental conditions. High productivity, early heading, medium stature, and tolerance to drought- or salinity stress are among the breeding objectives for foxtail millet. The objective of this study was to select F3 families of foxtail millet from the cross of Botok-10xICERI-6 by weighted selection index and assisted by SiDREB2-based SNAP marker. Genotyping of 178 F3 families using the SiDREB2-based SNAP marker resulted in 29 A/A genotypes, 121 A/G genotypes, and 28 G/G genotypes. Further evaluation was conducted on 48 F3 families consisting of 27 A/A genotypes and 21 A/G genotypes in an augmented randomized complete block design together with their parental genotypes (Botok-10xICERI-6) and three check genotypes (Mauliru-2, NTB-1, and Toraja). Plant height and heading time had high broad-sense heritability, whereas grain weight per plant had a moderate broad-sense heritability. Ten potential F3 families were selected based on a weighted selection index with 20% intensity, comprised of seven A/G genotypes and three A/A genotypes with a weighted selection index ranging from 0.84 to 3.76. The F3 family with pedigree numbers B10I6-15-136, B10I6-15-161, and B10I6-15-70 with A/A genotypes are considered putative transgressive segregants and could be continued to the next generation for further breeding process. [ABSTRACT FROM AUTHOR]

Multiple factors can affect the R1-nj purple kernel expression and seed set, reducing its efficiency in identifying haploids in maize. The complex interaction among the haploid inducer (HI), source germplasm (SG), and season (S) is inevitable in in vivo maize haploid induction but could be used through compatibility and stability tests. We tested five HI genotypes on 25 distinct source germplasm in two different seasons of tropical savanna in Thailand. The dry season was more suitable than the rainy season for haploid induction. We noticed varying degrees of R1-nj inhibition among the 25 tropical source germplasm, with some of them exhibiting significant issues with the R1-nj purple kernel expression. Therefore, using the R1-nj alone may not provide accurate ploidy identification in maize. Despite the intense R1-nj expression, haploid inducer BHI306 showed poor stability and compatibility with tropical source germplasm for pollination rate and seed set during the rainy season. The GGE biplot suggested KHI42 and KHI64 as the most compatible haploid inducers under their respective two different mega-source germplasm for the pollination rate and R1-nj seed set. These findings can guide breeders in selecting the most compatible and stable haploid inducers under varying conditions. [ABSTRACT FROM AUTHOR]

Implementing a cropping intensity program with rice cultivation four times a year (CI 400) can be achieved using early maturing varieties of rice. However, this development needs to pay attention to the adaptability of the varieties planted to ensure successful implementation. The adaptability approach is a combination of assessing stability and productivity potential. This concept has been developed and applied in several studies, including research on rice. However, this approach is considered less comprehensive because it is nonparametric and only focuses on one stability analysis. Therefore, a systematic integration of various stability analyses, including index methods, is needed to comprehensively assess adaptability, particularly for early-maturing rice in South Sulawesi. This region is characterized by a dynamic climate zone and is one of the top four highest rice producers in Indonesia. Meanwhile, this study aims to develop a comprehensive adaptability index and select the best early-maturing rice varieties, especially in South Sulawesi. The investigation was conducted in Bone, Soppeng, and Gowa over two seasons using a nested randomized complete block design, with organized replications in each environment (location-season). Additionally, there was a significant focus on the application of five early-maturing and two check rice varieties, with each factor repeated three times at each location, totaling 126 experimental units. The results showed that the adaptability index, by combining stability rank accumulation with yield min max standardization, was effective at assessing the yield potential and stability of early-maturing rice varieties in supporting CI 400. Inpari 13 had the best index value at 0.55, followed by Cakrabuana at 0.31; hence both were recommended as adaptive early-maturing rice varieties, especially in South Sulawesi. [ABSTRACT FROM AUTHOR]

Foxtail millet (Setaria italica L. Beauv.) is a grain-producing crop with high nutritional benefits and adaptability to broad environmental conditions. Indonesian local foxtail millet accessions are valuable genetic resources for crop improvement of the species. This study aims to assess the biodiversity of Indonesian local foxtail millet accessions and estimate their salinity tolerance level utilizing the SiDREB2-based SNAP marker and early evaluation at the seedling stage. Our results showed that eight Indonesian local foxtail millet accessions, namely Toraja, Mauliru-2, Hambapraing, NTB-1, ICERI-5, ICERI-6, Botok-4, and Botok-10, had high variability based on agro-morphological traits. The Hambapraing and Mauliru-2 were the potential accessions with high yield estimates (2.33 ton.ha-1 and 1.93 ton.ha-1) and early harvest time (<110 DAT). ICERI-6 was indicated as a salinity-tolerant genotype based on the SiDREB2-based marker and early salinity evaluation at the seedling stage, while Toraja, Mauliru-2, NTB-1, and Botok-4 were categorized as sensitive genotypes. Germplasm variability and the estimated salinity tolerance level of Indonesian local foxtail millet accessions presented in this study serve as essential information in the foxtail millet breeding for high productivity, early harvest time, and salinity tolerant variety. [ABSTRACT FROM AUTHOR]

The utilization of controlled greenhouses can be an alternative for melon (Cucumis melo L.) cultivation. Growing melon in greenhouses lowers the risk of pests and infections by diverse pathogens. Low solar irradiation during the rainy season and pollution in the greenhouse roof, may cause shade stress conditions for the plants inside. This study aimed to elucidate the plant and fruit characteristics of nine genotypes of melon grown under shade conditions in a greenhouse and the variability among them. The experiment was conducted in a greenhouse of Cikabayan Experimental Station, IPB University, Bogor, from November 2016 to January 2017. The genetic materials evaluated were nine melon genotypes from the Center for Tropical Fruit Studies at IPB University. A randomized complete block design with three replicates was followed. Shade intensity in the greenhouse was approximately 25%. The results showed that the genotype effect was significant for internode length, petiole length, plant height fruit, flesh thickness, fruit rind thickness, fruit weight, and total soluble solids. Genotype means for fruit weight were small in this experiment (< 300 g), whereas the total soluble solids were moderate to high (8.7-14.3 °Brix). Fruit diameter had a positive and significant correlation with leaf length, leaf width, and fruit length, whereasfruit weight had a positive and significant correlation with fruit diameter and fruit length. [ABSTRACT FROM AUTHOR]

Efficiency and effectiveness in controlling crossbreeding are pivotal in yielding superior hybrid varieties with desired traits such as genetic purity and high productivity. Cytoplasmic Male Sterile (CMS) is a crucial component in hybrid variety assembly. This study aims to identify the genotypes that can induce male sterile lines based on genetic diversity and the level of pollen sterility in the prospective male sterile genotypes tested, consisting of seventeen genotypes. The research findings revealed that the genetic diversity among the seventeen observed male-sterile candidate genotypes tends to vary in quantitative traits. Among the quantitative traits, JHD14 exhibited indications of being a male sterility inducer compared to the other genotypes observed, demonstrating a value of 0.00 g in terms of pollen weight. This is further substantiated by the microscopic examination of JHD14 pollen grains, which displayed 100% sterility. [ABSTRACT FROM AUTHOR]

Anther culture is a widely utilized technique in rice breeding because of its simplicity and effectiveness in rapidly obtaining pure lines in the form of doubled haploid plants. The selection of doubled haploid (DH) rice lines derived from anther culture in advanced yield trials is an important step for obtaining superior DH lines. We aimed to determine agronomic performance, including yield and yield stability in order to select lowland DH rice lines that are high yield and have good agronomic performance based on the selection index method. The research was conducted in Indonesia at three locations, i.e., Bogor (West Java), Indramayu (West Java) and Malang (East Java) from July to December 2022. The genotypes tested were 29 DH lines and three check varieties (Inpari-42 Agritan GSR, Inpari-18 Agritan and Bioni63 Ciherang Agritan) using a randomized complete block design (RCBD) with genotypes as a single factor and three replications. High heritability values are found in all agronomic characters, except the percentage of filled grain/panicle, the percentage of empty grain/panicle and productivity. The yield stability based on the Kang method showed that 15 lines were stable and had high productivity. Phenotypic correlation analysis showed that the number of productive tillers, days to flowering, days to harvesting, number of filled grains/panicle and percentage of filled grains all had positive values and significantly correlated with productivity. Phenotypic path analysis showed that the character of days to harvesting, number of filled grains/panicle, number of productive tillers and percentage of filled grains/panicle directly affected the productivity. Based on the weighted selection index, 12 DH lines were selected due to having a positive and higher index (8.54 to 0.28) than the Bioni63 Agritan and Inpari 18 check varieties. Among those lines, 9 DH lines were also stable based on the Kang Method. [ABSTRACT FROM AUTHOR]

Hybrid rice is derived from a cross between the cytoplasmic male sterile (CMS) as the female parent and the restorer line as the male parent. This study aimed to evaluate the ability of several new plant type (NPT) rice lines as restorers of the CMS female parent and to elucidate the performance of the hybrid combinations. The research was carried out from December 2019 to November 2020 at Babakan Sawah Baru Experimental Station, Department of Agronomy and Horticulture, IPB University, Bogor, Indonesia. The hybrids were evaluated in the field together with the CMS female parent, male parents, and two check varieties, namely Ciherang and hybrid P05 Prima Seed. The experimental design used was a randomized complete block design (RCBD) with two replications. The results showed that two male parental lines, IPB189-F-10-3-2 (T6) and IPB189-14-1-1 (T9), had a hybrid seed yield per hill of 66.04 g and 75.27 g, respectively. These two parents have the restorer gene (R) which is substantiated by the good characteristics of the number of filled grains and total grain per panicle of the two hybrids. The potential hybrids CMS x IPB189-F-10-3-2 and CMS x IPB189- 14-1-1 had a positive heterosis for panicle length and 1,000 grain weight, and could be evaluated in future research. [ABSTRACT FROM AUTHOR]

In vivo maternal haploid induction in isolation fields is proposed to bypass the workload and resource constraints existing in haploid induction nurseries. A better understanding of combining ability and gene action conditioning traits related to hybrid inducers is necessary to set the breeding strategy including to what extent parent-based hybrid prediction is feasible. This study aimed to evaluate the following in tropical savanna in the rainy and dry seasons for haploid induction rate (HIR), R1-nj seed set, and agronomic traits: 1) combining ability, line per se, and hybrid performance of three genetic pools; 2) genetic parameters, the modes of gene action, and heterosis; and 3) the relationships of inbred-general combining ability (GCA) and inbred-hybrid performance. Fiftysix diallel crosses derived from eight maize genotypes were evaluated in the rainy season of 2021 and the dry season of 2021/2022. Reciprocal cross effects including the maternal effect barely contributed to the genotypic variance for each trait observed. HIR, R1-nj seed set, flowering dates, and ear position were highly heritable and additive inherited, while ear length showed dominant inheritance. The equal importance of additive and dominance effects was found for yield-related traits. Temperate inducer BHI306 was the best general combiner for the HIR and R1-nj seed set, followed by two tropical inducers, KHI47 and KHI54. The ranges of heterosis were trait-dependent and slightly influenced by the environment, where hybrids in the rainy season consistently had higher heterosis than those in the dry season for each trait observed. Both hybrid groups derived from tropical × tropical and tropical × temperate inducers showed taller plants, larger ear size, and higher seed sets than the corresponding parents. However, their HIRs were still below the standard check of BHI306. The implications of genetic information, combining ability, and inbred-GCA and inbred-hybrid relationships on breeding strategies are discussed. [ABSTRACT FROM AUTHOR]

One essential objective of rice breeding is to obtain high-yielding varieties. This study aimed to (1) determine the effect of genotype (G), environment (E), and genotype by environment (GxE) interaction on agronomic traits and yield of 12 lowland rice genotypes, (2) estimate variance components and repeatability (3) identify promising rice genotypes with good agronomic performance and high yield potential. The trials were conducted in three irrigated lowland locations from June to November 2020, using a randomized complete block design with three replications. The results showed that the GxE interaction effect was significant on days to flowering, days to harvest, plant height, number of tillers, and panicle length. The genotype's main effect was significant on yield. Four IPB lines (IPB189-F-13-1-1, IPB189-F-23-2-2, IPB193-F-17-2-3, and IPB193-F-30-2-1) had a higher average yield than Ciherang and Inpari 32 varieties. The IPB189-F-23-2-2 had a panicle length stability across the three test locations and a higher average yield than the checks. [ABSTRACT FROM AUTHOR]