Basic HTML Version
Bt Research 2013, Vol.4 No.5 24-28
ISSN 1925-1939
http://bt.sophiapublisher.com
24
Research Report Open Access
Mismatch in Source and Sink as a Reason Determining Realized Potentiality of
Bt Cotton Hybrids
Yanal Ahmad Alkuddsi , S.S Patil , S.M. Manjula , B.C.Patil , K.J. Pranesh
,
S. Rajeev , P. Swathi ,
H.M. Ranganatha
K.J. Pranesh, S.Rajeev. P. Swathi and H.M. Ranganatha ARS Dharwad Farm, UAS Dharwad, Karnataka, 580005
Corresponding authors email: y.alkuddsi@gmail.com;
Authors
Bt Research, 2013, Vol.4, No.5 doi: 10.5376/bt.2013.04.0005
Received: 30 Jun., 2013
Accepted: 03 Sep., 2013
Published: 06 Dec., 2013
This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Alkuddsi et al., 2013, Mismatch in Source and Sink as a Reason Determining Realized Potentiality of Bt Cotton Hybrids, Bt Research, Vol.4, No.5 24-28 (doi:
10.5376/bt.2013.04.0005)
Abstract
The onset of Bt era has lead to increase in productivity of cotton in Indian scenario. Many of the hybrids commercialized
in the initial phase were those hybrids which were popular in non Bt era and some of them have failed to give same high productivity
in their Bt form. A comparison of Bt cotton hybrids for productivity, plant type features has revealed that though Bt cotton hybrids
revealed increased productivity some hybrids reveal early scenecense leading to a more determinate habit. The increase in yield in
these hybrids mostly comes from the bolls borne on the lower half of the plant than the upper half of the plant. There is a mismatch
between the source and sink especially in the upper half of the plant. These hybrids reveal visibly weakened leaves at a later stage as
a result of which they show reduced photosynthetic activity. As compared to this, some of the most potential hybrids remained green
and photosynthetically active enough to support the increased reproductive load. There is a fairly comparable harvest index in both
upper and lower halves. Thus these hybrids reveal higher productivity in both lower and upper halves of the plant canopy. This
observation has an important implication in plant breeding that the parents(at least one of them) chosen for developing Bt hybrids
should have strong photosynthetic system and stay green nature so that the hybrid is capable of withstand enhanced Bt gene induced
reproductive load.
Keywords
Bt gene; Cotton; Source and sink
Introduction
India ranks third in global cotton production after the
United States and China, and with 8-9 million hectares
grown each year, India accounts for approximately
25% of the world's total cotton area and 16% of global
cotton production. There are a number of benefits for
adopting transgenic cotton, including environmentally
safer pest control of major Lepidopterous insects,
improved safety and health conditions for farmers,
enhanced use of beneficial insects as biological
control agents, and lower cost of production and
higher yields (Edge et al., 2001).
Bt cotton is an increasingly important tool for farmers
around the world. Statistics provided in the report
indicates that 5.6 million small and marginal farmers
in India during the year 2009 planted and benefited
from 8.381 (~8.4) million hectares of Bt cotton,
equivalent to 87% of the 9.636 (~9.6) million hectare
national cotton crop. Large- and small-acreage
farmers benefit from increased productivity,
convenience, and time savings. The vast majority of
farmers using Bt cotton globally are smallholder
farmers who may reap economic, environmental, and
social benefits from adoption of this important tool for
agriculture. Adoption of this technology has led to
positive implications for the farmers, their
surrounding communities, and the future of
agriculture (Purcell and Perlak, 2004).
The relationship between source and sink is different
in the Bt cotton as compare to non Bt cotton,
especially during the early stage of the growth. The Bt
hybrids which are not able to put up sufficient
vegetative growth during early stage of growth face
with the problem mismatch source
–
sink relationship