scholarly journals SERANGAN DAN POPULASI Scotinophara sp. PADA TANAMAN PADI SAWAH DI KABUPATEN BOLAANG MONGONDOW TIMUR

EUGENIA ◽  
2019 ◽  
Vol 22 (3) ◽  
Author(s):  
Alex Hendra Kila ◽  
Ch. L. Salaki ◽  
E. R.M. Meray
Keyword(s):  
Population Density ◽  
Rice Plant ◽  
Survey Methods ◽  
Test Site ◽  
Rice Cultivation ◽  
Plant Age ◽  
Vegetative Stage ◽  
Rice Plants ◽  
Generative Phase

ABSTRACT The research aimed to find out the attacks and pest populations Scotinophara sp. in rice crops have been carried out in EastBolaang Mongondow from July to October 2014. The study used survey methods at several centers of rice cultivation in East Bolaang Mongondow, then set three districts as a test site where sampling. Sampling using Method Diagonal slices then select ten clump of rice plants in each sub-sample plots. Samples were taken at vegetative stage and generative phase. Things were observed in this study is the percentage of infected plants and pest populations. The results showed that the highest percentage of infected rice plants in the age of the plants 8 weeks after plants are found in Sub Tutuyan amounted to 66.66 percent and the lowest sequentially the District Nuangan and the District Kotabunan namely 39.33 percent and 11.13 percent.The highest Scotinophara sp. population density was found based on the location is district Tutuyan 10,11 tail and the lowest sequentially District Nuangan and the District Kotabunan is 1.82 and 0.96 tail. The density of the population by age of the plant, the highest in the plant age 8 mst 12.75 and the lowest sequentially 6, 4 and 2 mst is4.38, 0.06 and 0 tail.Keywords : attack, population, Scotinophara sp., rice plant

SERANGAN DAN POPULASI Scotinophara sp. PADA TANAMAN PADI SAWAH DI KABUPATEN BOLAANG MONGONDOW TIMUR

EUGENIA ◽  
2019 ◽  
Vol 22 (3) ◽  
Author(s):  
Alex Hendra Kila ◽  
Ch. L. Salaki ◽  
Elisabeth R.M. Meray
Keyword(s):  
Population Density ◽  
Rice Plant ◽  
Survey Methods ◽  
Test Site ◽  
Rice Cultivation ◽  
Plant Age ◽  
Vegetative Stage ◽  
Rice Plants ◽  
Generative Phase

ABSTRACT   The research aimed to find out the attacks and pest populations Scotinophara sp. in rice crops have been carried out in EastBolaang Mongondow from July to October 2014. The study used survey methods at several centers of rice cultivation in East Bolaang Mongondow, then set three districts as a test site where sampling. Sampling using Method Diagonal slices then select ten clump of rice plants in each sub-sample plots. Samples were taken at vegetative stage and generative phase. Things were observed in this study is the percentage of infected plants and pest populations. The results showed that the highest percentage of infected rice plants in the age of the plants 8 weeks after plants are found in Sub Tutuyan amounted to 66.66 percent and the lowest sequentially the District Nuangan and the District Kotabunan namely 39.33 percent and 11.13 percent.The highest Scotinophara sp. population density was found based on the location is district Tutuyan 10,11 tail and the lowest sequentially District Nuangan and the District Kotabunan is 1.82 and 0.96 tail. The density of the population by age of the plant, the highest in the plant age 8 mst 12.75 and the lowest sequentially 6, 4 and 2 mst is4.38, 0.06 and 0 tail. Keywords : attack, population, Scotinophara sp., rice plant

scholarly journals A comparison of density estimation methods in plateau pika populations in an alpine meadow ecosystem

2020 ◽  
Vol 101 (4) ◽  
pp. 1091-1096
Author(s):  
Wanrong Wei ◽  
Jundong He ◽  
Qiaoyan Zheng ◽  
Yuli He ◽  
Maria K Oosthuizen
Keyword(s):  
Population Density ◽  
Relative Density ◽  
Alpine Meadow ◽  
Survey Methods ◽  
Estimation Methods ◽  
Plateau Pika ◽  
Relative Population ◽  
Burrow Density ◽  
The Absolute ◽  
Absolute Population

Abstract Plateau pikas are a keystone species and ecosystem engineers in alpine meadow ecosystems. A number of surveying methods have been used to estimate pika density, but the reliability of these methods is not known. In addition, better population density methodologies allow for more reliable density estimates. We therefore compared the relationship among several commonly used methods of estimating pika relative density and the absolute density (AD) of pika populations. This relationship was investigated in summer and winter pastures to determine whether distribution pattern of the pikas (patchy or uniform) would influence this relationship. During August of 2015 and August of 2016, we measured the relative and absolute population density of pikas in an alpine meadow in the County, Gansu province, northwestern China. Relative density was measured with three indirect and direct methods: the total burrow density (TBD), the active burrow density (ABD), and the direct counting density (DCD) at the peak of pika activity. AD was assessed by removal sampling. Our results showed that the relative population density with all three survey methods was significantly related to the absolute population density. In particular, DCD at the peak of the pika activity showed the best correlation with AD. A simple linear model showed the effect of grazing time by livestock had a significant effect on TBD and ABD. These results imply that using DCD as a method to survey at the peak of the pika activity is more reliable than other methods.

scholarly journals Food availability and larval density affect ovarian development in Plutella xylostella (L.) (Lepidoptera: Yponomeutidae)

1999 ◽  
Vol 28 (4) ◽  
pp. 611-616 ◽  
Author(s):  
Marina Castelo Branco ◽  
Alexander G. Gatehouse
Keyword(s):  
Population Density ◽  
Food Availability ◽  
Plutella Xylostella ◽  
Ovarian Development ◽  
Diamondback Moth ◽  
Larval Density ◽  
Leaf Disk ◽  
Plant Age ◽  
Insect Migration ◽  
Petri Dishes

The effect of Diamondback Moth (Plutella xylostella L.) population density and plant age on the rate of ovarian development was investigated. In tests carried out in Petri dishes, the density of larvae/leaf disk affected the rate of ovarian development. A high proportion of moths from larvae reared on leak disks from two or four-month-old spring cabbage at a density of seven or 14 larvae/leaf disk were mature at emergence. But moths reared at the same type of plant at a density of 28 larvae/leaf disk were largely immature at emergence. When the larvae were reared at a density of 30 larvae/plant on two or four-month-old spring cabbage plants, a high proportion of females were mature at emergence. Crowding has an important effect on the rate of ovarian development in Diamondback Moth with possible consequences for the migratory potential of moths, as insect migration generally occurs when the ovaries of the females are immature. The density of moths necessary to increase the proportion of immature females in the field is probably higher than 30 larvae/plant.

Changes in release level of momilactone B into the environment from rice throughout its life cycle

2003 ◽  
Vol 30 (9) ◽  
pp. 995 ◽  
Author(s):  
Hisashi Kato-Noguchi ◽  
Takeshi Ino ◽  
Masahiko Ichii
Keyword(s):  
Life Cycle ◽  
Release Rate ◽  
Rice Plant ◽  
Growth Inhibitor ◽  
Rice Plants ◽  
Flowering Initiation ◽  
Single Rice ◽  
Germination And Growth

Momilactone B was released into the neighboring environment from rice throughout its life cycle. The rate of momilactone B release from rice increased until flowering initiation, and then decreased. The release rate of momilactone B at the day of flowering started was 2.1 μg plant–1 d–1. On average, a single rice plant released about 100 μg of momilactone B into the neighboring environment over its life cycle. Since momilactone B is a growth inhibitor, these results suggest that momilactone B released from rice plants may serve as an allelochemical to inhibit the germination and growth of neighboring plants.

scholarly journals Spatiotemporal expression profile of novel and known small RNAs throughout rice plant development focussing on seed tissues

BMC Genomics ◽  
2022 ◽  
Vol 23 (1) ◽  
Author(s):  
Anikó Meijer ◽  
Tim De Meyer ◽  
Klaas Vandepoele ◽  
Tina Kyndt
Keyword(s):  
Plant Development ◽  
Early Life ◽  
Small Rnas ◽  
Rice Plant ◽  
Rice Yield ◽  
Small Interfering Rnas ◽  
Yield And Quality ◽  
Spatiotemporal Expression ◽  
Generative Phase ◽  
Generation Sequencing

Abstract Background Small RNAs (sRNAs) regulate numerous plant processes directly related to yield, such as disease resistance and plant growth. To exploit this yield-regulating potential of sRNAs, the sRNA profile of one of the world’s most important staple crops – rice – was investigated throughout plant development using next-generation sequencing. Results Root and leaves were investigated at both the vegetative and generative phase, and early-life sRNA expression was characterized in the embryo and endosperm. This led to the identification of 49,505 novel sRNAs and 5581 tRNA-derived sRNAs (tsRNAs). In all tissues, 24 nt small interfering RNAs (siRNAs) were highly expressed and associated with euchromatic, but not heterochromatic transposable elements. Twenty-one nt siRNAs deriving from genic regions in the endosperm were exceptionally highly expressed, mimicking previously reported expression levels of 24 nt siRNAs in younger endosperm samples. In rice embryos, sRNA content was highly diverse while tsRNAs were underrepresented, possibly due to snoRNA activity. Publicly available mRNA expression and DNA methylation profiles were used to identify putative siRNA targets in embryo and endosperm. These include multiple genes related to the plant hormones gibberellic acid and ethylene, and to seed phytoalexin and iron content. Conclusions This work introduces multiple sRNAs as potential regulators of rice yield and quality, identifying them as possible targets for the continuous search to optimize rice production.

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