GUWAHATI, Jan 23 - In its bid to develop climate change-resilient muga silkworm breeds, the Central Silk Board has already developed two breeds with higher shell weight and fecundity. Multi-locational trial of these breeds is under progress.
Silk Board sources told this correspondent that these two breeds of muga silkworm have been named as CMR-1 and CMR-2.
Also, a project on oxidative stress is under progress to identify the beneficial heat shock on muga silkworm. Another new project has also been formulated to study on carbon dioxide accumulation and the climate change-induced rise in the temperature and its consequential impact on muga silkworm rearing.
Besides, preponing and postponing of muga rearing to avoid climatic hazard has been initiated in different muga growing regions of the State.
Since muga silkworms are wild, domestication process for this species of silkworms and rearing it with artificial food in indoors is also taken up as a regular programme and research project.
The Silk Board has been making collaborative efforts too with IIT Guwahati, IIT Kharagpur, Centre for DNA Fingerprinting and Diagnostics (CDFD) of Hyderabad, Seribiotechnology Research Laboratory (SBRL) of Kodathi and Jorhat-based North East Institute of Science and Technology (NEIST) with the aim at developing climate change-resilient muga silkworm breeds applying the genetic engineering technology.
The Silk Board is also trying to develop disease-resistant muga silkworm breed. However, here in this area, the main problem it is facing has emerged from the mono race peculiarity of the muga species of the silkworms.
It needs mention here that muga silkworm is a mono race species with slight morphological variations it undergoes due to the variable climatic condition in different locations of the northeastern region. These variations are not genetic and may not be sustained throughout a long period. Therefore, while developing such breeds the Silk Board has to backcross the muga silkworms with their parental stock to obtain their desired characters.
A maximum temperature ranging between 26 degree Celsius and 28 degree Celsius is ideal for the growing and maturing of the muga silkworms. But in the last five to six years, the summer crop of muga faced a lot of climatic variability. High temperature, and, sometimes untimely rainfall, cause larval mortality and thereby affect the overall production and productivity of muga.
Similarly, the winter crops are also facing heavy fog, which causes occurrence of fungal infection. The favourable temperate autumn season for Katia crop rearing is becoming warmer, affecting its desired harvest. Similar developments are also observed in the case of the Jethua crop rearing during the early summer period.
The adverse impact of climate change on the muga sector has led to shortage of quality seed cocoon, deformed moth emergence, false coupling or pairing, occurrence of depressed and unfertilized eggs, poor hatching and occurrence of protozoan, viral, bacterial and fungal diseases, among others, due to temperature fluctuation and humidity and high percentage of Uzi fly infestation.
To adapt to the changes brought about by climate change in the weather condition, the muga silkworms should be disease-resistant and acclimatise with variations in the climatic condition. The muga breeds should be high-yielding and have the quality silk producing capacity, sources asserted.