Brown planthopper is the most important rice pest in Indonesia. Its high adaptability to feed and reproduce on previously introduced resistant varieties to form more virulent population often causes BPH outbreak and hopperburn that lead to total crop yield loss. Rice breeding for resistant to BPH requires information on the current status of BPH virulences in the fields to anticipate the virulence adaptation on new varieties. The objectives of this study were to investigate the degree of virulence of BPH populations and to cluster the BPH virulence to form BPH core collection. Thirteen BPH populations collected from paddy fields in six provinces (Banten, West Java, Central Java, East Java, South Kalimantan, and South Sulawesi) in 2011 and 2013 were tested on 10 differential rice varieties and seven host varieties of BPH populations, using the standard seedbox screening technique. Based on resistance reaction of four differential varieties (TN1, Mudgo, ASD7, and Rathu Heenathi), most BPH populations were identified as more virulent than biotype 4 (T1, Banten, PG, West Java; BY, East Java; B2 and B3, South Kalimantan; X1 and X3, South Sulawesi), four populations were biotype 4 (JWDL, Central Java; SD, East Java; X2 and X4, South Sulawesi), and one population each was biotype 3 (T2, Banten) and biotype 2 (S1, West Java). Populations X1 and B3 showed broad virulences to all varieties, whereas T2 was the least virulent. BPH field’s population had evolved into more virulence than biotype 4. Genotype resistance screening should use the BPH of this virulence population. Five BPH clusters which were further divided into 10 subclusters representing differential virulence toward 10 differential varieties were present in the tested BPH. Each virulence cluster was characterized by its ability to overcome four to eight single or double resistant genes. This BPH virulence core collection can be used in the characterization studies of candidate for resistant varieties or to form near-isogenic lines, or to study the insect and rice plant interaction.
Early-maturing and high-yielding rice variety is very useful for increasing rice production in Indonesia. The aim of this research was to develop new lines of Indonesian rice containing Hd2 gene using Code variety as a recipient parent and Nipponbare variety as a donor parent through targetted MAB approach using RM1362 and RM7601 in chromosom 7 for foreground selection. After two generations of backcrossing, the positive alleles of Hd2 gene from Nipponbare had successfully trans-ferred into Code. The plant number CdNp_29 in BC2F2 popula-tion had the highest genome recovery of 82.7%. The twelve BC2F3 plants were selected for self-pollination to generate BC2F4. These selected lines that carried the Hd2 gene were screened in the greenhouse for the evaluation of heading date and agronomic traits. All improved lines had Hd2 gene similar to the donor parent Nipponbare. The heading date of the breeding lines ranged from 73 to 89 days (Code 85 days) or fill the third criterion of rice maturity that is 103-104 days compared to Code of 116-119 days, whereas their agronomic performances were similar with that of Code. Application of MABc for im-proving rice early maturity has accelerated the development and selection in early generation of superior lines having genetic background of Code. It is expected that the newly developed lines of Code will be utilized to increase rice production in Indonesia.
<p>Brown planthopper (BPH) is a major rice pest in Indonesia. The most economical and effective approach to control the insect pest is by using resistant varieties. Exploring for resistance genes is, therefore, a prerequisite for effective breeding program for BPH resistance. This study aimed to map BPH resistance genes in Untup Rajab, an Indonesian local rice variety. Genetic map was constructed using an F2 population from a cross between TN-1 and Untup Rajab, and SNP markers from RiceLD SNP Chip. Phenotyping was performed using bulk seedling test on F2:3 seedlings against two BPH populations, i.e. X1 and S1. Four QTLs<br />were identified on chromosomes 5, 6, 8, and 11 with PVE values of 7.63%, 9.40%, 17.66%, and 3.05%, respectively. Relatively normal distribution of resistance phenotype and the relatively low PVE values indicate that Untup Rajab has a quantitative resistance to BPH with two different resistance loci identified for each BPH test population. The QTL on chromosome 8 overlaps with OsHI-LOX gene, which is associated with resistance to BPH, and adjacent to another QTL for resistance to green leafhopper. The QTL on chromosome 6 was found near OsPLDα4 and OsPLDα5 genes which are related to BPH resistance. Meanwhile, the QTL intervals on chromosome 5 and 11 did not overlap with any known BPH QTLs or genes, which make them attractive candidates for novel BPH resistance gene discovery.</p>
Availability of fertile land on the island of Java in Indonesia decreases due to the shifting from agricultural land to non-agricultural land. Hence, an extensification of soybean culture to outer Java suboptimal land areas is needed, such as tidal swamp which occupies approximately 20.192 million hectares. The main limitations in this soil are soil acidity, Fe toxicity and excess water. To develop soybean varieties tolerant to acid tidal swamp, tolerant soybean gene resources are needed. Hence, glasshouse and field experiments were carried out to identify tolerant gene resources. The glasshouse experiment has been conducted using 185 genotypes of germplasm at the Indonesian Legume and Tuber Crops Research Institute, Malang, East Java. Selection was carried out by using a selection index method. The glasshouse experiment was followed by field experiment at the Belandean research station, Banjarbaru, South Kalimantan, using the best 17 genotypes selected from the glasshouse trial. Results showed that there was variability of response of each genotype to acidity and Fe toxicity. Therefore, assessment of soybean tolerance to acidity and Fe toxicity should be conducted by root growth. Based on selection index criteria, varieties of Lawit and Menyapa served as check tolerant varieties and showed lower growth than the 17 selected genotypes. In the field experiment, genotype MLGG 1087 was identified as the most tolerant and can serve as a gene resource tolerant to acid tidal swamp because it has the highest relative root growth on root dry weight, and the highest average of root and shoot dry weight
Early-maturing and high-yielding rice variety is very useful for increasing rice production in Indonesia. The aim of this research was to develop new lines of Indonesian rice containing Hd2 gene using Code variety as a recipient parent and Nipponbare variety as a donor parent through targetted MAB approach using RM1362 and RM7601 in chromosom 7 for foreground selection. After two generations of backcrossing, the positive alleles of Hd2 gene from Nipponbare had successfully trans-ferred into Code. The plant number CdNp_29 in BC2F2 popula-tion had the highest genome recovery of 82.7%. The twelve BC2F3 plants were selected for self-pollination to generate BC2F4. These selected lines that carried the Hd2 gene were screened in the greenhouse for the evaluation of heading date and agronomic traits. All improved lines had Hd2 gene similar to the donor parent Nipponbare. The heading date of the breeding lines ranged from 73 to 89 days (Code 85 days) or fill the third criterion of rice maturity that is 103-104 days compared to Code of 116-119 days, whereas their agronomic performances were similar with that of Code. Application of MABc for im-proving rice early maturity has accelerated the development and selection in early generation of superior lines having genetic background of Code. It is expected that the newly developed lines of Code will be utilized to increase rice production in Indonesia.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.