Development of Transgenic CryIA(c) + GNA Cotton Plants via Pollen-Tube Pathway Method Confers Resistance to Helicoverpa armigera and Aphis gossypii Glover

Author(s):  
Zhi Liu ◽  
Zhen Zhu ◽  
Tianzhen Zhang
2020 ◽  
Vol 13 (4) ◽  
pp. 125
Author(s):  
IG.A.A. INDRAYANI ◽  
SIWI SUMARTINI

<p>ABSTRAK<br />Hingga kini teknik perakitan varietas kapas tahan hama masih<br />dilakukan secara konvensional berdasarkan beberapa karakter morfologi<br />tanaman, seperti: bulu daun, daun okra, braktea berpilin, nektar, dan<br />gosipol tinggi. Karakter-karakter ini diketahui erat hubungannya dengan<br />ketahanan terhadap hama, khususnya H. armigera. Berkaitan dengan<br />serangan H. armigera pada buah, diduga ada bagian-bagian buah kapas<br />yang berkontribusi secara langsung pada serangan hama ini, misalnya<br />braktea buah. Namun demikian, besarnya pengaruh braktea terhadap<br />kerusakan buah kapas perlu dipelajari dalam upaya meminimalkan<br />kerusakan. Penelitian ini bertujuan untuk mengetahui pengaruh ukuran<br />braktea terhadap tingkat kerusakan buah oleh H. armigera pada beberapa<br />aksesi kapas. Penelitian dilaksanakan di Kebun Percobaan Balai Penelitian<br />Tanaman Tembakau dan Serat, di Asembagus, Situbondo, Jawa Timur<br />mulai bulan Januari hingga Desember 2006. Sebanyak 18 aksesi dari 50<br />aksesi kapas dengan berbagai variasi ukuran braktea digunakan sebagai<br />perlakuan. Setiap perlakuan (aksesi) disusun dalam rancangan acak<br />kelompok (RAK), dengan tiga kali ulangan. Lima tanaman kapas dari<br />masing-masing aksesi ditentukan secara acak, dan sebanyak 5 buah kapas<br />muda (diameter ± 4 cm) dipetik dari masing-masing tanaman sampel,<br />kemudian dibawa ke laboratorium untuk diukur luas braktea dan buahnya.<br />Selain itu dilakukan pula pengamatan kerusakan buah dan hasil kapas<br />berbiji di lapang. Hasil penelitian menunjukkan bahwa ukuran braktea<br />berkorelasi positif dengan tingkat kerusakan buah (R 2 = 0,9014), sehingga<br />braktea berukuran besar dan lebar serta menutupi buah secara total<br />berpotensi mengalami kerusakan akibat serangan H. armigera lebih tinggi<br />dibanding braktea berukuran kecil dan sempit. Ukuran panjang dan lebar<br />braktea pada 18 aksesi kapas bervariasi antar aksesi dan masing-masing<br />berkorelasi positif dengan luas (R 2 = 0,876; R 2 = 0,894). Hasil penelitian<br />ini dapat dimanfaatkan dalam merakit varietas tahan hama, dan<br />kombinasinya dengan karakter-karakter morfologi kapas yang sudah ada<br />untuk menghasilkan varietas kapas baru dengan tingkat ketahanan yang<br />lebih tinggi terhadap hama penggerek buah H. armigera.<br />Katakunci : Braktea, Helicoverpa armigera, aksesi kapas, karakter<br />morfologi.</p><p><br />ABSTRACT<br />Effects of bract size of several cotton accessions to<br />American bollworm injury level<br />Conventional  method  by  crossing  technique  based  on<br />morphological characters of plant is now still used in providing resistant<br />varieties of cotton against insect bollworms. A number of genetic<br />characters are now available and have been studying for their assosiation<br />with insect pests resistance such as hairiness, okra leaf, frego bract,<br />nectariless, and high gossypol. Regarding to boll damage by H. armigera,<br />it can be mentioned that there are many other morphological characters of<br />cotton attributable to bollworm damage, such as floral bract. As a part of<br />boll, it is estimated that bracts assosiated with bollworm attacked due to<br />their larger size compared with boll size. Objective of the study was to find<br />out the effect of bract size in relation to bollworm damage on cotton<br />accessions. The study was conducted at Experimental Station of<br />Indonesian Tobacco and Fiber Crops Research Institute in Asembagus,<br />Situbondo, East Java from January to December 2006. Eighteen of fifty<br />cotton accessions were used as treatment and they were arranged in<br />Randomized Block Design (RBD) with three replications. Five randomly<br />cotton plants from each accession and five young bolls were sampled<br />from the selected plant with about 4 cm of diameter were brought in the<br />laboratory to collect information on bract and boll sizes. Bollworm<br />damage was determined by counting the damaged bolls in the field as well<br />as the seed cotton yield. Result showed that bract size was positively<br />correlated with boll damage (R 2 = 0.9014). Higher damaged bolls occured<br />on bolls which is covered completely by bracts. There is variation between<br />length and wide size of bracts among cotton accessions and both showed<br />positive correlation to bract area (R 2 = 0.876; R 2 = 0.894). Based on this<br />study, higher resistance of cotton variety against H. armigera will<br />possiblly be provided through combination between bract size and any<br />other morphological characters of cotton.<br />Key words : Floral bract, Helicoverpa armigera, cotton accession,<br />morphological character</p>


2005 ◽  
Vol 30 (3) ◽  
pp. 307-315 ◽  
Author(s):  
Xiang Dong Liu ◽  
Bao Ping Zhai ◽  
Xiao Xi Zhang ◽  
Jian Min Zong

2016 ◽  
Vol 106 (6) ◽  
pp. 710-717 ◽  
Author(s):  
T.T.A. Luong ◽  
S.J. Downes ◽  
B. Cribb ◽  
L.E. Perkins ◽  
M.P. Zalucki

AbstractIn Australia Bt cotton has been planted since 1996, and has greatly improved the control of its key target Helicoverpa armigera (Hübner). There is no strong evidence that genetically modified cotton has been selected for significant physiological resistance to Bt toxin in field populations. There are many possible explanations for the lack of apparent selection that range from high compliance with the resistance management strategy for this technology to a lack of behavioral preference in key traits such as oviposition that could favor survival. To date most experiments that test oviposition of H. armigera on Bt cotton vs. conventional cotton have been done with susceptible moths. We determine the oviposition preference of a field isolated Bt resistant line of H. armigera and a susceptible counterpart when given a choice of non-Bt cotton and Bt-cotton with the same genetic background, and test whether there is any relationship between oviposition site selection (different plant structures) and the survival of the first instar larvae. Within cotton plants, our experiments consistently showed that both resistant and susceptible moths did not choose plants or plant parts that were less toxic in terms of Bt toxin on which to lay eggs. There was one exception in that susceptible moths were more likely to lay eggs on squares of Bt cotton plants than squares of non-Bt cotton. As expected, the mortality of susceptible H. armigera neonates was significantly higher on structures of Bt cotton plants than on those structures of conventional cotton, and survival was greater on flowers than on other structures of Bt cotton. This confirms opportunities for selection for resistance, and demonstrates no advantage in this respect to carrying resistance genes that might overcome the Bt toxins.


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