Judul: Pengaruh Pengeringan, Media Pengujian, Waktu Panen dan Kondisi Ruang Simpan terhadap Viabilitas Serbuk Sari Mentimun (Cucumis sativus L.).
Abstrak: The objectives of this research were to study the decline of cucurbits pollen viability during desiccation, to determine the suitable germination medium for cucumber pollen, to determine the best time for pollen harvesting and to study thestorability of Cucumis sativus pollen. The study was carried out during March- August 2011 at Production Farm and Pollen Laboratory, PT East West Seed Indonesia in Jember, East Java. Viability of pollen harvested on the day of anthesis decreased after anther drying in air-conditioned room for 24 hours and decreased further after pollen drying in MgCl2 for 24 hours. Viability of pollen harvested one day before anthesis increased after anther drying in airconditioned room for 24 hours, then decreased after drying in MgCl2 for 24 hours. PGM 1, PGM 2 (modified from the original), Brewbacker and Kwack (BK), E1, and E2 were pollen germination medium used in this experiment. The male parental stock of KE010, KE014, KE018, and KE019 were used as the pollen source. The result showed that KE014 pollen germinated in PGM 1 had higher germination than BK, on the first trial. In the second trial, PGM 1 also showed higher germination than E2. Pollen of KE010, KE018, and KE019 germinated in PGM 2 produced higher germination than PGM 1 in in the third trial. The pollen harvesting was done at 07.00, 09.00, 11.00, 13.00, 15.00, 17.00 one day before anthesis and on the day of anthesis (A-1 and A) on KE010, KE018, KE019. The result showed that the best time for pollen harvesting for the three varieties was during 07.00-11.00 on the day of anthesis with viability at about 35%. The storage conditions under investigation for cucumber pollen were freezer, deep freezer, and ultra freezer. The most suitable storage condition for cucumber pollen (KE010, KE018, KE019) was ultra freezer, in which viability of cucumber pollen more than 1% would keep for 42 HSS (6 weeks), 90 HSS (12 weeks), 9 HSS (1.5 weeks) without any significant decline on germination.
Keyword: 

Judul: Cytological Mechanism of Pollen Deterioration and Its Potential in Bitter Gourd (Momordica charantia L.) Seed Production
Abstrak: Pengelolaan serbuk sari memiliki peran penting dalam produksi benih hibrida Cucurbitaceae, dengan tantangan utama pada viabilitas serbuk sari yang menurun dengan cepat. Tujuan dari penelitian ini adalah untuk mendapatkan informasi periode reseptif stigma paria, mempelajari daya simpan dan mekanisme penurunan viabilitas serbuk sari paria selama penyimpanan dan untuk mengetahui potensi serbuk sari paria yang disimpan untuk produksi benih. Penelitian dilaksanakan di Kampus Institut Pertanian Bogor (IPB), Dramaga Bogor, pada bulan September 2018 hingga Juni 2021. Pengamatan ultrastruktur sel dilakukan di laboratorium TEM dan Histologi, Lembaga Eijkman, Jakarta. Periode reseptif stigma diamati secara visual dan berdasarkan fruit set dan seed set dari waktu penyerbukan berbeda (pukul 07.00; 09.00; 11.00; 13.00; dan 15.00). Serbuk sari paria dipanen pada saat bunga mekar kemudian disimpan dalam deep freezer kisaran suhu (-24) hingga (-18) ºC. Pengamatan viabilitas serbuk sari dilakukan pada serbuk sari segar, 0, 2, 4, 6, 8, 10, dan 12 minggu setelah simpan (MSS), sedangkan ultrastruktur serbuk sari pada serbuk sari segar, 4, 8, dan 12 MSS. Serbuk sari yang disimpan juga digunakan untuk penyerbukan di lapangan, kemudian diamati produksi dan mutu benih yang dihasilkan. Hasil penelitian menunjukkan bahwa periode reseptif stigma paria aksesi No 9 (Balitsa) terjadi antara pukul 07.00-11.00. Penyimpanan serbuk sari dalam deep freezer kisaran suhu (-24) hingga (-18) ºC hanya dapat mencegah penurunan viabilitas sampai 4 minggu. Penurunan viabilitas disebabkan oleh degenerasi dinding sel (exine) dan membran mitokondria yang mulai terlihat pada 4 MSS. Exine, membran luar dan dalam mitokondra mengalami degenerasi total pada 12 MSS. Serbuk sari paria yang telah disimpan dalam deep freezer kisaran suhu (-24) hingga (-18) ºC sampai dengan 2 minggu efektif untuk produksi benih bermutu., Pollen management has an essential role in hybrid seed production of Cucurbitaceae, with a significant challenge on the rapid decline of pollen viability. The aims of the research were to obtain information on the bitter gourd stigma receptive period, to study the mechanism of pollen deterioration of bitter gourd during storage, and to investigate if stored pollen is as effective as fresh pollen for seed production. The research was carried out at Dramaga Campus of IPB University from September 2018 to June 2021. Cell ultrastructure observations were carried out at the TEM and Histology Laboratory, Eijkman Institute, Jakarta. The stigma receptive period was observed visually and based on fruit set and seed set from a different pollination time (07.00; 09.00; 11.00; 13.00; and 15.00 h). Bitter gourd pollen was harvested at anthesis and then stored in the deep freezer at a temperature around (-24) to (-18) ºC. Observation on viability was done on fresh pollen, 0, 2, 4, 6, 8, 10, and 12 weeks after storage (WAS), while pollen ultrastructure was on fresh pollen, 4, 8, and 12 WAS. The stored pollen was also used for pollination in the field. Seed production as well as seed quality were observed. The result showed that the stigma receptive period for bitter gourd accession No 9 (Balitsa) occurred between 07.00-11.00 h. Pollen stored in a deep freezer (ranged (-24) to (-18) ºC) would inhibit the declining viability for up to 4 weeks. The declining
Keyword: exine, fruit set, intine, mitokondria, seed set

Judul: Invers Drazin dari Matriks Toeplitz Singular
Abstrak: Matriks Toeplitz adalah matriks yang setiap unsur pada diagonal utama bernilai sama dan setiap unsur pada subdiagonal yang bersesuaian dengan diagonal utama juga bernilai sama. Matriks singular adalah matriks yang tidak bisa ditentukan inversnya. Akan tetapi, dapat diupayakan untuk ditentukan inversnya menggunakan invers matriks yang diperumum. Invers Drazin merupakan salah satu jenis invers matriks yang diperumum. Pada karya ilmiah ini ditentukan invers Drazin dari matriks Toeplitz singular dengan menggunakan metode Leverrier Faddeev. Kemudian, ditentukan invers Drazin dari matriks Toeplitz singular yang direpresentasikan sebagai penjumlahan segitiga bawah dan segitiga atas matriks Toeplitz berdasar pada teorema Gohberg dan Semencul., Toeplitz matrix is a matrix in with element on the main diagonal has the same value and on the subdiagonal corresponding to the main diagonal also has the same value. Singular matrix is a matrix that has no inverse. However, it can be attempted to determine the inverse using a generalized inverse matrix. Inverse Drazin is a type of generalized matrix inverse. This paper discussed the inverse Drazin for a singular Toeplitz matrix using the Leverrier Faddeev method. Then, the Drazin inverse of the singular Toeplitz matrix which is represented as a sum of products of lower and upper triangular Toeplitz matrix based on Gohberg and Semencul theorem.
Keyword: inverse Drazine, singular Toeplitz matrix