north american academic research research evaluation of seed … · 2019-03-09 · pg. 52 north...

pg. 50 North American Academic Research , Volume 2, Issue 3 – March ; 2019, 2(3) : 50-57 ©TWASP,

USA

North American Academic Research

Contents lists available at : www.twasp.info

Journal homepage: http://twasp.info/journal/home

Research

Evaluation of Seed Quality and Health of Some Aus Rice Genotypes

Md. Sadiqur Rahman1*, Taslima Jahan2, Monjur Morshed3, Md. Riyadh Arefin4, Dr. M.

Moynul Haque 5 1Scientific Officer, Regional Agricultural Research Station, Bangladesh Agricultural

Research Institute, Moulvibazar, Bangladesh 2Scientific Officer, Plant Genetic Resources Centre, Bangladesh Agricultural Research

Institute, Bangladesh 3Department of Soil Science, Bangabandhu Sheikh Mujibur Rahman Agricultural University,

Gazipur–1706, Bangladesh 4Scientific Officer, Bangladesh Tea Research Institute, Bangladesh 5Professor, Seed Technology Division, Bangabandhu Sheikh Mujibur Rahman Agricultural

University, Gazipur–1706, Bangladesh

*Corresponding Author :

Md. S. Rahman

Email: [email protected]

Mobile: 01714492070

Published online : 05 March, 2019

Abstract: An experiment was conducted at Seed Technology and Plant Pathology laboratory of

Bangabandhu Sheikh Mujibur Rahman Agricultural University to evaluate the seed quality and

health of some Aus rice genotypes viz. Chehrang Sub1, Shengyon 11-25, Shengyon 11-26, NERICA

10, Pariza, BU dhan1, and BRRI dhan48 were used in this experiment. Significant variation in

respect of germination (%), germination rate, leachate conductivity, normal seedling (%), un-

germinated fresh seed (%) and pathogenic infection was observed in different genotypes. Among

the genotypes, BRRI dhan48 had a higher percentage of germination and normal seedling with

higher germination rate having lower leachate conductivity. In the case

of pathogen, Fusarium moniliforme was dominant, and its prevalence was highest in Chehrang Sub1

genotype and in the case of Alternaria padwickii the highest prevalence was observed in Pariza

genotype. The percent of abnormal seedlings and the pure live seed of all genotypes were

statistically similar. Among the treatments, germination % was lowest in BU dhan1. The highest

lethal seed infection was caused by Fusarium moniliforme;

Alternaria padwickii and Curvularia lunata also caused lethal seed infection, might have an effect on

germination rate and leachate conductivity.

Keywords: Germination rate,leachate conductivity, prevalence of seed borne fungi

http://www.twasp.info/

http://twasp.info/journal/home


USA

Introduction:

Seed health refers primarily to the presence or absence of disease-causing organisms such as

fungi, nematodes, bacteria, viruses, and insects associated with seed. Physiological conditions

such as trace element deficiency may also affect seed health (ISTA 1985). Farmers often use

seeds that have impurities and contaminants and are infected with pathogens (Fujisaka,

Guino, Lubigan, and Moody1993,149-157). The importance of seed quality in realizing the

full potential of a variety is well known. The three major aspects of seed quality are a) genetic

and physical purity, b) high germination percentage and vigor, and c) free from seed-borne

diseases and insects (Seshu and Dadlani 1989). Seed vigor is recognized as an important seed

quality parameter distinct from germinability (Seshu, Krishnasamy and Siddique 1988, 315-

329). According to Thomson (1979), high-quality seed is a critical input on which all other inputs

will depend on for their full effectiveness. If the seed is not standard quality, the use of other inputs

is less useful. Production is affected due to inferior seed quality and incurred economic loss due to

misuse of other inputs. Inferior seeds may decrease production. Quality means suitability for its

sowing to achieve a satisfactory yield. In general, this is determined by the quality components of

seed. The components are seed size, purity, moisture content, germination percentage, seed

health, viability, and seed vigor, etc.

Healthy seeds play a vital role in improving the yield of any crop. They carry the genetic

characteristics for successful crop production. It is important that healthy seeds must be used

as planting materials in order to increase crop productivity. Contaminated seeds can often

result in poor germination, poor seedling vigor, and unhealthy crop. The deterioration of the

seed vigor in crops accounted for 20 percent of the yield losses (Shenoy, Paris and Duff

1988). The present investigation was carried out to establish whether seed-borne fungi are

responsible for seedling abnormalities, the possibility of combining germination tests and

seed health tests to determine the effect of seed treatments and seed processing procedures on

germination and seedling vigor.

Materials and Methods:

The experiment was conducted at Seed Technology and Plant Pathology laboratory of

Bangabandhu Sheikh Mujibur Rahman Agricultural University. A total of seven seed samples

were collected from the harvested rice seeds viz. Chehrang Sub1, Shengyon 11-25, Shengyon

11-26, NERICA 10, Pariza, BU dhan1, and BRRI dhan48, and kept in the Seed Technology

Laboratory of Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU),


USA

Gazipur. Quality and health attributes of the harvested seeds were determined according to

ISTA rules.

Purity analysis

The purity analysis of seed sample was performed to determine the pure seed, contamination

with inert materials, weed seeds and seeds of other crops. A working sample of 70 g was

drawn from each sample and spread on the purity analysis board provided with a light source

and a magnifying lens. From the working sample, inert materials, weed seeds, seeds of other

crops, insects damaged seeds, spotted seeds were separated manually. The weight of the

individual component was measured using digital electric balance having a capacity of 0.001-

400 g. The results were expressed in percentage based on the gross weight of the working

sample using the following formula:

The weight of the individual component/gross seed weight x 100

Germination test

Seeds were tested for germination capacity. From each sample, four replicates of one hundred

seeds were counted at random from well-mixed pure seed fraction. Seeds were placed

uniformly and adequately apart on three layers of moist filter paper substrate in 21 cm x 15.5

cm germination trays. Germination trays were kept in germinator maintained at 20ͦ C for 16

hours in dark and 30ͦ C for 8 hours with light for a total period of 14 days. Each and every

seedling was evaluated according to general principals laid down in ISTA rules in 2006. The

classification was made as a normal seedling, abnormal seedling, diseased seeds, and non-

germinated fresh seeds. Germination percentage was calculated as:

Number of seeds germinated

Germination (%) = ---------------------------------------- x 100

Number of seeds tested

Seed vigor (Leachate conductivity)

For electrical conductivity test, 50 gm seeds of each sample were taken in a conical flask

containing 50 ml de-ionized water and incubated at 20ͦ C for 20 hours; water of the beaker

containing seeds was decanted in order to separate the seeds. The electrical conductivity was

measured by the EC meter. Four replications of measurements were made for each sample of

seed and expressed in μs/cm.


USA

Seed viability

Seed viability was tested by tetrazolium salt test. A hundred seeds were soaked in 1%

colorless tetrazolium salt for 24 hours. The experiment was repeated three times, where the

colored embryo indicates viable seeds.

Germination rate

Germination rate (GR) was calculated from a daily count of germinated seeds until it reached

a constant value and calculated as:

GR= +……… +

Pure live seed

To calculate pure live seed (PLS), the percentage of pure seed is multiplied by the percent

germination (percent normal seedling) and the product is divided by 100.

% pure seed x % normal seedling

PLS (%) = --------------------------------------------------

100

Seed dormancy

The percentage of dormancy was calculated by deducting the germination percentage from

viable seed percentage.

Seed health testing

Seed health of rice i.e. fungi associated with the seed samples was tested by Standard blotter

method (Marcinkowska 2002). Three layers of sterilized wet filter paper (Whatman filter

paper no.1) were placed in the bottom of 9 cm Petri dishes. In this test, 400 seeds per sample

were used and 25 rice seeds were placed on filter paper of each Petri dish. The Petri dishes

containing seeds were incubated at 25±2ͦ C in an incubator for 7 days. The incubated seeds

were examined under a stereomicroscope and different fungi grew from seeds were

identified. For proper identification of fungi, temporary slides were prepared from the fungal

colony and observed under a compound microscope. The prevalence was expressed in

percentage based on the total number of seeds planted.


USA

Statistical analysis

All data were subjected to statistical analysis by analysis of variance (ANOVA). Microsoft

EXCEL and R stat program software. Means were separated using Duncan’s Multiple Range

Test (DMRT) at a significance level of 0.001, 0.01 and 0.05 (Gomez, Gomezand

Gomez1984).

Results and discussion:

Seed quality:

Germination percentage differed significantly among the different genotypes (Table 1). BRRI

dhan48 had the highest germination percentage (95.25%) which was statistically similar to

those of Chehrang Sub1, Shengyon 11-25 and Pariza. The lowest germination percentage was

recorded in BU dhan1 (89.67%) which was followed by Shengyon 11-26 and NERICA 10

(Table 1).

The level of seed dormancy did not vary significantly among the genotypes. It varied

from 3.83 to 7.83% depending upon the genotypes. Basically, indica rice show either non-

dormant, moderate or strong dormancy according to their growing seasons. But when rice is

sown in the Aus season, it shows non-dormant to moderate dormancy. In the present study,

seeds of different genotypes showed moderate dormancy which might be due to genetic

make-up and prevailing in seed formation and development of the variety.

The germination rate of seeds obtained from different genotypes differed when compared to

the germination percentage. BRRI dhan48 had the highest germination rate and the lowest

leachate conductivity. It also produced the highest pure live seeds while the maximum

percent of purity was observed in BU dhan1.

Purity is an important indicator of seed quality, while the pure live seed is a more important

indicator of seed quality because it expresses both purity and germination. In the present

study, all genotypes gave more than 85.53% pure live seed which indicates good quality seed.


USA

Table 1. Seed and Seedling quality attribute of different Aus rice genotypes

Rice

genotypes

Germination% Dormancy

(%)

Viability% Germination

rate

Leachate

conductivity

(µs cm-1)

Purity

(%)

PLS

(%)

Chehrang

Sub1 92.67 ab 3.83 96.7 23.09 b 49.57 ab 95.78 88.43

Shengyon

11-25 92.67 ab 4.67 97.3 23.85 b 45.67 ab 95.02 88.02

Shengyon

11-26 90.83 b 5.83 96.7 24.33 ab 25.23 c 94.16 85.53

NERICA

10 91.83 b 5.5 97.3 23.81 b 44.23 ab 95.78 87.96

Pariza 92.75 ab 4.58 97.3 24.18 ab 49.91 ab 93.61 86.84

BU dhan1 89.67 b 7.83 97.7 23.28 b 51.33 a 96.16 86.41

BRRI

dhan48 95.25 a 4.08 99.3 25.46 a 18.10 c 96 91.45

CV (%) 1.77 33.35 1.27 3.09 26.93 1.94 2.88

Sig. Level * ns ns * ** ns ns

Means followed by same letter(s) in a column are not significantly different by DMRT.

Seedling quality

Parameters related to germination capacity of rice seeds, in terms of normal seedlings,

abnormal seedlings, diseased seeds and non-germinated fresh seeds in samples of seven

categories are presented in Table 2.

The percentage of normal seedlings varied significantly among the genotypes. The highest

percentage of normal seedlings was recorded in BRRI dhan48 (93.58%) which was

statistically identical to Chehrang Sub1 (91.25%) and Pariza (91.42%). The percentage of

normal seedlings was recorded in BU dhan1 (87.83%) which was statistically identical to

Shengyon 11-25 (89.98%), Shengyon 11-26 (89.25%) and NERICA 10 (89.58%).

Where the percentage of abnormal seedlings and diseased seedlings did not vary significantly

among the rice genotypes.


USA

Table 2. Seedling quality attributes of different Aus rice genotypes

Rice genotypes Normal seedling% Abnormal

seedling%

Un-germinated

Fresh seed%

Diseased

seedlings%

Chehrang sub1 91.25 ab 1.58 3.92 cd 3.25

Shengyon 11-25 89.98 bc 2.75 5.50 bc 1.83

Shengyon 11-26 89.25 bc 1.58 7.08 ab 2.08

Nerica 10 89.58 bc 2.35 6.58 ab 1.58

Pariza 91.42 ab 1.33 3.50 d 3.75

BU dhan1 87.83 c 2 8.33 a 1.75

BRRI dhan48 93.58 a 1.67 2.917 d 1.83

CV (%) 1.53 38.43 18.02 49.41

Sig. Level ** ns *** ns

Means followed by same letter(s) in a column are not significantly different by DMRT.

Health status of harvested seed samples of different Aus rice genotypes

A total of five species of fungi was detected in different seed samples of different genotypes.

In order of prevalence, they were Fusarium moniliforme,

Alternaria padwickii, Curvularia lunata, Aspergillus spp, Bipolaris oryzae (Table3). The

prevalence of all other fungi except Fusarium moniliforme was recorded low, where the

prevalence of Bipolaris oryzae was recorded very low and absent in Chehrang Sub1, BU

dhan1, and BRRI dhan48.

Table 3. Prevalence of major seed borne fungi associated with seeds of different Aus

rice genotypes

Rice Genotype

% Seed borne fungi

Fusariummo

niliforme

Alternariap

adwickii

Curvularial

unata

Aspergillus

spp.

Bipolaris

Oryzae

Chehrang Sub1 17.58 4.67 2.42 1.55 0.00

Shengyon 11-25 9.50 2.17 2.61 1.00 0.52

Shengyon11-26 7.66 3.34 1.53 0.90 1.04

NERICA 10 11.83 2.17 2.16 1.67 0.40

Pariza 6.17 4.61 1.67 2.61 2.66

BU dhan1 9.67 4.33 3.16 2.16 0.00

BRRI dhan48 4.67 2.27 1.63 1.05 0.00


USA

Conclusion

Prevalence of Fusarium moniliforme and Alternaria padwickii might have an effect on

germination rate because the maximum prevalence of these two fungi was recorded in

Chehrang Sub1 which might have an effect on the lowest germination rate (23.09) of

Chehrang Sub1. Germination rate (23.28%) of BU dhan1 was also lower than that of the

other five genotypes having a sound percentage of prevalence of these two fungi.

There is also a possibility of having more electrophorage leakage on seed surface which

permits releasing more ions as more affected by Curvularia lunata because leachate

conductivity was recorded highest of 51.33 µscm-1 in BU dhan1 and also the highest (3.16%)

prevalence of Curvularia lunata. It was also observed in Chehrang Sub1 having 49.57 µscm-1

leachate conductivity and 2.42% prevalence of Curvularia lunata. Whereas the lowest (18.10

µs cm-1) leachate conductivity was observed in BRRI dhan48 with a lower percentage

(1.63%) of the prevalence of Curvularia lunata.

Reference:

Fujisaka, Sam, Ricardo A. Guino, R. T. Lubigan, and Keith Moody. "Farmers' rice seed

management practices and resulting weed seed contamination in the

Philippines." Seed science and technology 21, no. 1 (1993): 149-157.

Gomez, Kwanchai A., Kwanchai A. Gomez, and Arturo A. Gomez. Statistical procedures for

agricultural research. John Wiley & Sons, 1984.

ISTA, 1985. International Seed Testing Association. International Seed Testing Association

rule book. Seed Sci. and Technol. 13(2): 299-520.

ISTA. 2006. International Rules for Seed Testing. The International Seed Testing Association.

Zurich, Switzerland.

Marcinkowska, J. Z. "Methods of finding and identification of pathogens in seeds." Plant

Breeding and Seed Science 46, no. 1 (2002).

Seshu, D. V., and MalavikaDadlani. "Role of women in seed management with special

reference to rice." (1989).

Seshu, D. V., V. Krishnasamy, and S. B. Siddique. "Seed vigor in rice." Rice seed health. Los

Banos, Philippines: International Rice Research Institute (1988): 315-329.

Shenoy, Sandhya N., T. R. Paris, and B. Duff. "Farm Level Harvest and Post-Harvest Seed

Management Practices of Farm Women in an Irrigated Rice System: A Case Study

Paper presented at “Women in rice farming system network orientation and planning


USA

workshop” held at the lnternational Rice Research lnstitute." Los Baños, Laguna,

Philippines(1988).

Thomson, J.R. 1979. An introduction to seed technology.1-87. East Kilbride: Thomson

Litho Ltd.

© 2019 by the authors. TWASP, NY, USA. Author/authors are fully responsible for the text, figure, data in above pages. This

article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license

(http://creativecommons.org/licenses/by/4.0/)

http://creativecommons.org/licenses/by/4.0/

north american academic research research evaluation of seed … · 2019-03-09 · pg. 52 north...

Documents