STUDY ON MOLECULAR DIVERSITY, HETEROSIS, COMBINING ABILITY AND SEED VIGOR IN ...

225 Pages·2017·58.35 MB·English

STUDY ON MOLECULAR DIVERSITY, HETEROSIS,
COMBINING ABILITY AND SEED VIGOR IN
SORGHUM [Sorghum bicolor (L.) Moench]

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Submitted to the

G.B. Pant University of Agriculture & Technology,

Pantnagar-263145 (U.S. Nagar), Uttarakhand, INDIA

By

Priyamvada Chauhan
M.Sc.Ag. (Seed Science & Technology)

IN PARTIAL FULFILMENT OF THE REQUIREMENTS
FOR THE DEGREE OF

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(Seed Science & Technology)

AUGUST, 2016
ACKNOWLEDGEMENT

First of all I bow my head and express gratitude with all reverence and devotion to
“ ”
the Almighty for showering his blessings. He is the one who has given me a chance to
acknowledge whole-heartedly all those who have provided me utmost support all through my

thesis research.
The words at my command are inadequate to express my most sincere gratitude to
my Advisor Dr. P.K. Pandey, Assistant Professor, Department of Genetics and Plant
Breeding, College of Agriculture, G.B. Pant University of Agriculture and Technology,
Pantnagar, for his timely and generous guidance, diligent planning, constant encouragement,
whole hearted corporation, constructive criticism and analytical perusal of the manuscript
during the entire period of my research work and thesis writing. He has been tremendous

mentor for me. His advice on both research as well as on my career have been priceless.
I am immensely thankful to the members of my advisory committee, Dr. P. K.
Shrotria, Professor (Department of Genetics and Plant Breeding), Dr. P.S. Shukla,
Professor (Department of Genetics and Plant Breeding) and Dr. N.K. Singh, Professor
(Department of Genetics and Plant Breeding) who gave me their valuable suggestion and

guidance throughout my research work.
’
I owe my indebtedness to the Honble Vice-Chancellor, Director Experiment Station,
Dean, Post Graduate Studies and Dean, College of Agriculture, G.B.P.U.A.& T.,
Pantnagar for providing opportunity and necessary facilities for the conduct of Ph. D.

research.
I wish to thank Dr. Shivji Singh, Mr. Rajendra Junior Scientist, Mr. Ajeet Kumar
Field Assistant, and Mr. Rajesh, clerk, Ravindra, Raju, Mahesh and Deepu, and sorghum
breeding staff for providing valuable technical help and support in data collection and
Processing. The research work which seemed tough and insurmountable became easy and
smooth going because of field staff Mr. Bechan ji, Mr. Kushwaha ji and others who stood

beside me in time of need.
I am highly obliged and gratefully indebted to Dr. Kamendra Singh, Professor,
Dr. Rajendra Prasad, Professor, Dr. Birendra Prasad, Associate Professor, Dr. J.P. Jaiswal,
Professor, Dr. M.K. Nautiyal, Professor, Dr. M.K. Karnwal, J.R.O., Dr. Usha Pant, J.R.O
and other teaching staff Department of Genetics and Plant Breeding for their valuable and
indispensable suggestions, positive disposition, help, support, and friendly atmosphere

provided during my thesis work.
I cherished the generosity, constant encouragement and company of my dear friend
Geeta Pandey, Priyanka Agarwal, Anupam Barh and my seniors Dr. Pankaj Kumar,
Vandana Bhakuni and juniors Archana Parki, Pratima Raypa, Vaishali Verma and

Pooja Pandey for their affection, help and support.
The words fail to express my deep sense of indebtedness to my parents, my brother
Anurag Singh and my sister Ragani Chauhan who brings me up to this stage and for all the

blessing and love they showered on me.
I am highly thankful to Department of Science and Technology, New Delhi for

awarding the INSPIRE Fellowship during my doctoral degree programme.
Lastly thanks to all beloved and respected people around me who directly and
indirectly helped during my degree programme and whose names could not be mentioned
here.

Pantnagar (Priyamvada Chauhan)

August, 2016 Authoress
CERTIFICATE

This is to certify that the thesis entitled "STUDY ON MOLECULAR
DIVERSITY, HETEROSIS, COMBINING ABILITY AND SEED VIGOR
IN SORGHUM [Sorghum bicolor (L.) Moench]” submitted in partial
fulfilment of the requirements for the degree of Doctor of Philosophy with major
in Seed Science and Technology and minor in Genetics and Plant Breeding of
the College of Post Graduate Studies, G.B. Pant University of Agriculture and
Technology, Pantnagar, is a record of bona fide research carried out by Ms.
Priyamvad Chauhan, Id. No. 44333 under my supervision and no part of the
thesis has been submitted for any other degree or diploma.
The assistance and help received during the course of this investigation
have been duly acknowledged.

Pantnagar (P.K. Pandey)
August, 2016 Chairman
Advisory Committee
CERTIFICATE

We, the undersigned, members of the Advisory Committee of Ms.
Priyamvad Chauhan, Id. No. 44333, a candidate for the degree of Doctor of
Philosophy with major in Seed Science and Technology and minor in Genetics
and Plant Breeding, agree that the thesis entitled " STUDY ON
MOLECULAR DIVERSITY, HETEROSIS, COMBINING ABILITY AND
SEED VIGOR IN SORGHUM [Sorghum bicolor (L.) Moench]” may be
submitted in partial fulfillment of the requirements for the degree.
C O N T E N T S
S. No. CHAPTER Page No.
1. INTRODUCTION
2. REVIEW OF LITERATURE
3. MATERIALS AND METHODS
4. RESULTS AND DISCUSSION
5. SUMMARY AND CONCLUSION
LITERATURE CITED
APPENDICES
VITA
ABSTRACT
Introduction
INTRODUCTION
Chapter 1

Sorghum ranks 5th in cereals for global production after wheat, rice, maize
and barley. Sorghum belongs to family Poaceae and is a genus with many species and
subspecies with several types like grain sorghums, grass sorghums (for pasture and
hay), sweet sorghums (for syrups), and broomcorn. It is a major crop for many poor
farmers, especially in Africa, Central America, and South Asia and is also considered
to be a significant crop for animal feeds. Sweet sorghums have higher silage yield, but
grain sorghums have higher nutrition due to the grains, therefore sweet sorghum
farmers may plant soybeans along with sorghum to raise the nutritional value of the
silage. Sorghum fibers are used in wallboard, fences, biodegradable packaging
materials, and solvents. Dried stalks are used for cooking fuel, and dye can be
extracted from the plant to color leather. A more recent use of sorghum is for ethanol.
By-products from ethanol production, such as sorghum-DDGS (distillers dried grains
with solubles), are also finding a place in the market.
Sorghum has major advantages compared with its competitive crops because it
can produce high yield under extreme environmental conditions. It can tolerate
drought, water-logging, and saline-alkali soils. These tolerance and adaptations are
because of its morphological and physiological characteristics. It produces many
roots, can reduce transpiration rate due to less leaf area and a waxy coating, remain
dormant during drought and can resume growth when conditions are favourable, can
compete well with weeds in an advanced stage, and has high net photosynthesis
compared to other cereals.
The genus Sorghum comprises a high genetic diversity (Abu Assar et al.,
2005 and Uptmoor et al., 2003) and therefore, has a potential for the crop
improvement. The wild distribution and high genetic diversity of sorghum in Africa
indicate that this crop must have originated in this continent. Sorghum [S. bicolor (L.)
Moench] is indigenous to Africa and many of today’s varieties originated on that
continent. Sorghum was also grown in India before recorded history and in as early as
700 BC. The crop reached China during thirteenth century. Sorghum was introduced
in USA from Africa in the early part of 17 th century.
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Introduction ……….
Globally, sorghum is grown on of 39.61 million hectares area with the
production of 61.82 million tons annually. In India, though there is no record on area
under forage sorghum, however based on seed production and its demand, it is
estimated to be around 0.8 to 0.9 million ha with 6.7 million tons of grain production
per annum (USDA Foreign Agriculture Service, 2012) mainly concentrated in north
western including UP, Uttarakhand, Delhi, Punjab, Haryana, Gujarat, Rajasthan and
Madhya Pradesh. India is the second largest producer of sorghum in the world, the
yield of 840 kg per hectare is the lowest amongst the major sorghum-producing
countries in the world. The world average is 1435 kg per hectare. Although yield of
sorghum in India is much lower than the world average, it has been consistently
increasing during the recent past. Sorghum is grown in the kharif (rainy season) and
rabi (post rainy season) but the share of kharif is higher both in terms of area under
cultivation and production. Rabi crop is almost entirely used for human consumption
whereas kharif crop is not very popular for human consumption but also is used for
animal feed, starch, and alcohol industry. Only 5 per cent of the area under sorghum
in India is irrigated. Over 48% of the area under sorghum cultivation in the country is
in Maharashtra and Karnataka.
Before initiating any crop improvement program, it is necessary to understand
the genetic nature of the parents. Combining ability analysis helps in identifying the
heterotic parents which can be used in hybridization program for the production of
superior hybrids. As a general rule, general combining ability (GCA) is the result of
additive gene effects, while the specific combining ability (SCA) is the result of non-
allelic interactions (Jinks, 1954). The estimates of combining ability are very useful
to predict the relative performance of different lines in hybrid combinations. The
information on the nature and magnitude of gene action is important in understanding
the genetic potential of a population and deciding the breeding procedure to be
adopted in a given population (Pfeiffer et al., 2010).
The term heterosis was coined by Shull in 1914. Heterosis can be defined as
the superiority or inferiority of F hybrid over both of the parents in terms of yield and
1
other attributes and is the most exploited but least understood phenomenon in plant
breeding program. Sorghum is an often cross pollinated crop and for that reason it can
be exploited both for additive and epistatic components by developing hybrids.
Combining ability analysis proposed by Griffing (1956) has widely been used in crop
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Introduction ……….
plants for identifying the best combiner to exploit heterosis or link up fixable
favorable genes that may lead to the development of superior genotypes (Agrawal et
al., 2005). It also helps in the characterization of nature and magnitude of gene action
for various characters of economic importance. Line x tester method (Kempthorne,
1957) is an important bi-factorial mating design for combining ability analysis which
estimates of genetic parameters are derived from half-sib and full-sib relationships of
parents. Male sterility is an important tool for the production of commercial hybrids in
many crops including sorghum. The A cytoplasm has been used in nearly all females
1
in hybrid sorghum production. CMS plants of A cytoplasm have small pointed
1
anthers and typically meiosis is normal but the microspores remain uninucleate and
abort (Singh and Hadley 1961). Twenty one additional sources of cytoplasms that
confer male sterility in sorghum have been described (Schertz et al. 1989). Despite
these discoveries, A1 cytoplasm is the primary CMS system used for hybrid seed
production.
India is one of the ancient agrarian societies. Nearly seventy percent of the
country’s population of over 123 crores is still dependent on Agriculture. Among all
inputs in agriculture production system, seed is the critical and most important input.
High quality seed is becoming increasingly important for farmers' profit
maximization, and seed vigor testing is the best solution for this purpose. Since good
seedling establishment precedes high yield, many suggestions have been made in
order to predetermine in the laboratory for the prediction of the ability of a given seed
lot to germinate and produce healthy seedlings under field conditions. Seed quality
can be assessed by using different laboratory tests which can help farmers to predict,
stand establishment and yield response before they even sow their seeds
(Naderidarbaghshahi).
The evaluation of vigor tests for predicting seed planting value is important in
providing better results for ranking the quality of seed lots than the standard
germination test. Many vigor test methods have been proposed by different
organizations viz., Anonymous (1993), Anonymous (2002) and the results obtained
from their studies showed differences among vigor tests used. Many research workers
have reported significant correlation coefficients between field emergence and
standard laboratory germination tests but they have also reported inconsistencies and
difficulties with the prediction of field performance of seeds. The methodology of
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Introduction ……….