Genetic analysis of tolerance to rice tungro bacilliform virus in rice (Oryza sativa L.) through agroinoculation

Balimau Putih [an Indonesian cultivar tolerant to rice tungro bacilliform virus (RTBV)] was crossed with IR64 (RTBV, susceptible variety) to produce the three filial generations F1, F2 and F3. Agroinoculation was used to introduce RTBV into the test plants. RTBV tolerance was based on the RTBV level in plants by analysis of coat protein using enzyme-linked immunosorbent assay. The level of RTBV in cv. Balimau Putih was significantly lower than that of IR64 and the susceptible control, Taichung Native 1. Mean RTBV levels of the F1, F2 and F3 populations were comparable with one another and with the average of the parents. Results indicate that there was no dominance and an additive gene action may control the expression of tolerance to RTBV. Tolerance based on the level of RTBV coat protein was highly heritable (0.67) as estimated using the mean values of F3 lines, suggesting that selection for tolerance to RTBV can be performed in the early selfing generations using the technique employed in this study. The RTBV level had a negative correlation with plant height, but positive relationship with disease index valu

Effects of IR34 on green leafhopper, Nephotettix virescens (distant) and its rice tungro virus transmission

Abstract onlyThis study was designed to determine the effects of IR34 resistance on the green leafhopper (Nephotettix virescens) and its rice tungro virus transmission. Studies were conducted on (1) nymph survival, number of adults produced by 3 pairs, and adult longevity of green leafhopper reared continuously for 5 generations on IR34 and (2) the rice tungro virus transmission by green leafhopper reared continuously for 5 generations on IR34. Rearing of green leafhopper on the resistant variety IR34 for 5 generations resulted to a progressive increase in the survival of nymphs, number of adults produced by 3 pairs, and adult longevity. Consequently, the rice tungro virus transmission on IR34 also improved. Although there was an improvement in the overall performance of the colony continuously reared on IR34, the performance on IR34 was still not comparable to that on susceptible TN1 variety. This indicate that 5 generations of continuous rearing was not enough for the colony to survive, reproduce, and transmit the rice tungro virus effectively on the resistant variety. However, it is clearly shown that the IR34 reared insects were different from those maintained on TN1 and could be considered as a distinct strain of green leafhopper.International Rice Research Institute (IRRI)Includes bibliographical referencesMaster of Science (Plant Pathology

Evaluating Two Mass Screening Methods for Tungro Disease Resistance

Tungro is one of the most destructive viral diseases of rice in South and Southeast Asia. It is associated with two viruses---rice tungro bacilliform virus (RTBV) ,and rice tungro spherical virus (RTSV) (Hibino et al 1978). Both viruses are transmitted by the green leafhopper (GLH) Nephotettix virescens (Ling 1979), However, prior acquisition of RTSV is required for Ihe transmission of RTBV alone (Hibino 1983). Plants infected with both viruses show severe stunting and yellowing. Those infected with RTBV alone show mild stunting but no leaf discoloration whereas those infected with RTSV alone do not show any apparent symptoms (Hibino el al 1978). Since the late 1960s, tungro has been mainly managed through varietal resistance (Khush 1989). The instability of resistant varieties in the field (Dahal et .a1 1990) led to a reexamination of the nature of the incorporated sources of resistance and to the adoption of more precise and more accurate screening methods

Cluster Analysis on Sustainable Transportation : The Case of New York City Open Data

Artificial Intelligence (AI) provides the opportunity to analyze complex transportation domains from various perspectives. Sustainability is one of the important transportation factors vital for a robust, fair, and efficient living environment and the livability of a city. This article leverages different feature engineering techniques on the New York City mobility dataset to identify the significant sustainability factors and employ the k-means clustering technique to cluster the commuters based on their transportation modes and demographics. Cluster analysis is performed based on the specified features and sustainable mode of transportation. Our cluster analysis of commuters on the New York City dataset shows that demographic information such as gender or race does not influence the sustainable mode of transportation, while the "start location"of travellers and their car access are influencing factors on sustainability. © 2022 IEEE.</p