Judul: Mikobiota pada buah apel : pengaruhnya terhadap colletotrichum acutatum, cendawan penyebab busuk pahit
Abstrak: Colletotrichum acutatum merupakan cendawan patogen penyebab busuk pahit pada berbagai buah-buahan, diantaranya apel. Salah satu pengendalian penyakit pascapanen pada buah-buahan yang memberikan harapan adalah penggunaan agens kontrol biologi. Penelitian ini bertujuan untuk menguji potensi antagonistik mikobiota pada buah apel terhadap C. acutatum. Cendawan patogen tersebut diisolasi dari 2 varietas buah apel (Malang dan Manalagi) yang berasal dari beberapa pasar tradisional dan pasar swalayan di Bogor dan Jakarta. Isolasi cendawan patogen dilakukan menggunakan metode pelempengan langsung (direct plating). Isolat cendawan yang diuji sifat antagonistiknya terhadap C acutatum berasal dari buah apel yang juga diperoleh dari pasar tradisional dan pasar swalayan di Bogor dan Jakarta, dan buah apel yang langsung dipetik dari kebun apel di Batu (Malang). Isolasi cendawan uji dilakukan menggunakan metode pengenceran yang dilanjutkan dengan metode cawan tuang pada media Malt Extract Agar (MEA) yang mengandung kloramfenikol; uji antagonisme dilakukan dengan metode oposisi langsung pada media MEA; uji patogenisitas isolat C. acutatum dan cendawan uji dilakukan dengan menginokulasikan isolat cendawan pada buah apel. Aplikasi satu isolat cendawan antagonis yang berpotensi sebagai agens kontrol biologi dilakukan dengan cara menginokulasi 0.1 suspensi konidium dengan berbagai konsentrasi ( 1 * 10 ^ 6 ; 2 * 10 ^ 6 4 * 10 ^ 6 6 * 10 ^ 6 8 * 10 ^ 6 1 * 10 ^ 7 konidium/ml) pada apel. Sembilan belas isolat C. acutatum telah diisolasi dari 2 varietas apel. Isolat C. acutatum AUD 20 mempunyai sifat patogenisitas tertinggi pada apel Malang (55.9%) dan apel Manalagi (52.2%). Sebanyak 49 isolat cendawan uji diisolasi dari apel, 8 isolat diantaranya dapat menghambat pertumbuhan C. acutatum lebih dari 50%. Walaupun demikian, hanya 6 isolat yang tidak menyebabkan penyakit pada kedua varietas apel. Salah satu isolat cendawan antagonis yang kemungkinan dapat digunakan sebagai agens kontrol biologi yaitu Pestalotiopsis guepinii. Berbagai konsentrasi suspensi konidium cendawan antagonis tersebut belum dapat menghambat busuk pahit secara efektif. Walaupun demikian, P. guepinii dengan konsentrasi 4 x 10° konidium/ml yang diinokulasikan bersama dengan 0.1 ml suspensi konidium C. acutatum ( 1 * 10 ^ 6 konidium/ml) dapat menghambat busuk pahit dengan persentase hambatan tertinggi (39.47%).
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Judul: Mycobiota on chilli fruits: their effect on colletotrichum capsici, causing anthracnose
Abstrak: Colletotrichum capsici merupakan cendawan patogen penyebab antraknosa pada berbagai buah tropis, terutama pada buah cabai. Penggunaan agens kontrol biologi merupakan alternatif pengendalian penyakit pascapanen pada produk hortikultura. Penelitian ini bertujuan untuk menguji potensi antagonistik mikobiota pada buah cabai terhadap C. capsici. Cendawan patogen dan cendawan uji diisolasi dari buah cabai merah besar var. Imperial-308 dan Hibrida F1 Maraton yang diperoleh dari 3 pasar tradisional di Kotamadya Bogor. Isolasi C. capsici menghasilkan 4 isolat. Colletotrichum capsici CPB I.1 memiliki patogenisitas tertinggi pada buah cabai merah besar var. IPB Perbani. Isolasi cendawan uji dilakukan dengan menggunakan metode pengenceran serial yang dilanjutkan dengan metode cawan tuang menghasilkan 14 isolat, terdiri atas 7 isolat cendawan berfilamen dan 7 isolat khamir. Uji antagonisme dilakukan dengan menggunakan metode oposisi langsung pada media Potato Dextrose Agar (PDA) menghasilkan 4 isolat cendawan antagonis yang menyebabkan persentase hambatan pertumbuhan lebih dari 70% terhadap C. capsici CPB I.1, yaitu 3 isolat cendawan berfilamen (Plectosphaerella cucumerina, isolat MF 2, dan Aspergillus flavus) dan 1 isolat khamir (Issatchenkia orientalis). Dua cendawan antagonis (P. cucumerina dan I. orientalis) tidak menyebabkan penyakit pada buah cabai var. IPB Perbani, sehingga berpotensi sebagai agens kontrol biologi., Colletotrichum capsici is a pathogenic fungus causing anthracnose on various tropical fruits, especially chilli fruit. Biological control agents have been used as an alternative to control postharvest diseases. This study aims to examine the antagonistic potential of mycobiota on chilli fruit against C. capsici. Pathogenic fungus and test fungi were isolated from red chilli fruits var. Imperial- 308 and Hibrida F1 Maraton collected from 3 traditional markets in Municipality of Bogor. Four isolates of C. capsici were obtained from red chilli fruits infected by anthracnose. Colletotrichum capsici CPB I.1 showed the highest pathogenicity on red chilli fruits var. IPB Perbani. Fourteen isolates of test fungi were obtained from healthy red chilli fruits using serial dilution method, followed by pour plate method. They consisted of 7 filamentous fungi and 7 yeast isolates. Test of antagonism using direct opposition method on PDA obtained 4 antagonist fungal isolates which inhibited the growth of C. capsici CPB I.1 more than 70%. They consisted of 3 filamentous fungi (Plectosphaerella cucumerina, isolate MF 2, and Aspergillus flavus) and 1 yeast (Issatchenkia orientalis). Two isolates of antagonist fungi (P. cucumerina and I. orientalis) did not cause any diseases of chilli fruits var. IPB Perbani, consequently they can be used as biocontrol agents. Keywords: anthracnose, chilli fruit, Colletotrichum capsici, mycobiota
Keyword: antraknosa, buah cabai, Colletotrichum capsici, mikobiota

Judul: The Construction of Greedy SVP LLL Algorithm
Abstrak: A lattice is a set of all integer linear combination of a set of linearly independent vectors in ℝ𝑛���. The independent vectors are called bases of lattice. Any lattice can be generated from many bases, and these bases have the same cardinality. In the lattice, the most fundamental and renowned problem is the Shortest Vector Problem (SVP). SVP is a tracking problem of the shortest nonzero vector in a lattice with equivalent bases. In two dimensions, SVP problem has resolved exactly by Gauss’ algorithm. When the lattice dimension is higher than two, A.K. Lenstra, H.W. Lenstra and L. Lovasz gave a LLL algorithm to compute approximation of nonzero shortest vector in the lattice. Reduced bases solution obtained from LLL algorithm still be an approximation and has polynomial running time of arbitrary dimension which large enough. In 1994, Schnoor and Euchner modified this LLL algorithm as a new variant which later was named deep insertion LLL algorithm. This algorithm is a modified version of the LLL algorithm to the terms of the exchange step to improve the accuracy of output of LLL reduced bases and applying it to the subset sum problem. The purpose of this research are: (1) Reconstruct the LLL algorithm and deep insertion LLL algorithm using a geometric approach. (2) Construct a greedy SVP LLL algorithm. (3) Implement the three algorithms in a symbolic programming language, and evaluate them experimentally. A bases ℬ=[𝐛���1,𝐛���2,…,𝐛���𝑛���] in ℝ𝑚��� is called reduced LLL with parameter 𝛿��� if satisfies: (a) |𝜇���𝑗���𝑖���|≤12, for every integer 𝑖���,𝑗��� with 1≤𝑖���<𝑗���<𝑛���. (b)𝛿���‖𝜋���𝑗���(𝐛���𝑗���)‖2≤‖𝜋���𝑗���(𝐛���𝑗���+1)‖2, for 𝑗���=1,2,…,𝑛���−1,where 𝛿��� is a reduced parameter of real numbers with 14<𝛿���<1. The first requirement is the reduced basis 𝛿��� must “nearly orthogonal” and in its computation case, this requirement can be reached out by using the Gram-Schmidt’s orthogonalization. While the second requirement is called exchange step, or used to called as Lovasz condition. By using both of these requirements, then they establish the LLL algorithm. Then, Schnoor and Euchner modify the LLL algorithm based on the requirements of the exchange step called the deep insertion LLL algorithm, where the exchange step is based on the comparison of the projected vector in orthogonal complement [𝐛���1,𝐛���2,…,𝐛���𝑘���−1]⊥ after j-th reduction. To construct greedy SVP LLL algorithm, the requirements of the exchange step is based on purely by comparing norm of lattice 𝐛���𝑗��� with norm lattice 𝐛���𝑖��� for 𝑖���=1,2,3…,𝑗���−1. The process of insertion reduced vector after the exchange step also has done greedily. Then, we calculate the number of arithmetic operation in greedy SVP LLL algorithm for further analysis. The result of our exprimentation for three algorithms on the certain matrix size shows that the running time of the three algorithms increases propotional to the size of the matrix. The result also shows that by using 𝛿���=34 for the LLL algorithm and the deep insertion LLL algorithm, and the greedy SVP LLL algorithm which is a new variant made by using no parameter of 𝛿���, outperform of the other of two previous algorithm in terms of speed with the same output.
Keyword: LLL algorithm, LLL deep insertion algorithm, greedy SVP LLL algorithm